| Compensation and Retirement Disclosure [Abstract] | Period [Axis] |
|---|
2016-01-01 - 2016-12-31 |
|---|
Compensation and Retirement Disclosure [Abstract] | |
Funded status | The following table presents a reconciliation of benefit obligations and plan assets. | | | | | | | | | | | | | | | | | | Pension Benefits | | Postretirement Benefits | (In millions) | 2016 | | 2015 | | 2016 | | 2015 | Benefit obligation as of January 1 | $ | 2,821 |
| | $ | 3,019 |
| | $ | 23 |
| | $ | 29 |
| Changes in benefit obligation: | | | | | | | | Service cost | — |
| | 4 |
| | — |
| | — |
| Interest cost | 113 |
| | 112 |
| | — |
| | 1 |
| Participants' contributions | — |
| | — |
| | 4 |
| | 4 |
| Plan amendments | — |
| | (55 | ) | | — |
| | — |
| Actuarial (gain) loss | 68 |
| | (79 | ) | | (6 | ) | | (3 | ) | Benefits paid | (173 | ) | | (173 | ) | | (7 | ) | | (8 | ) | Foreign currency translation and other | (14 | ) | | (7 | ) | | 1 |
| | — |
| Settlement through group annuity purchase | (86 | ) | | — |
| | — |
| | — |
| Benefit obligation as of December 31 | 2,729 |
| | 2,821 |
|
| 15 |
|
| 23 |
| Fair value of plan assets as of January 1 | 2,267 |
| | 2,456 |
| | — |
| | — |
| Change in plan assets: | | | | | | | | Actual return on plan assets | 193 |
| | (18 | ) | | — |
| | — |
| Company contributions | 9 |
| | 10 |
| | 3 |
| | 4 |
| Participants' contributions | — |
| | — |
| | 4 |
| | 4 |
| Benefits paid | (173 | ) | | (173 | ) | | (7 | ) | | (8 | ) | Foreign currency translation and other | (15 | ) | | (8 | ) | | — |
| | — |
| Settlement through group annuity purchase | (88 | ) | | — |
| | — |
| | — |
| Fair value of plan assets as of December 31 | 2,193 |
| | 2,267 |
| | — |
| | — |
| Funded status | $ | (536 | ) | | $ | (554 | ) | | $ | (15 | ) | | $ | (23 | ) | Amounts recognized on the Consolidated Balance Sheets as of December 31: | | | | | | | | Other assets | $ | 4 |
| | $ | 12 |
| | $ | — |
| | $ | — |
| Other liabilities | (540 | ) | | (566 | ) | | (15 | ) | | (23 | ) | Net amount recognized | $ | (536 | ) | | $ | (554 | ) | | $ | (15 | ) | | $ | (23 | ) | Amounts recognized in Accumulated other comprehensive income, not yet recognized in net periodic cost (benefit): | | | | | | | | Prior service credit | $ | — |
| | $ | — |
| | $ | (4 | ) | | $ | (6 | ) | Net actuarial loss | 999 |
| | 999 |
| | (3 | ) | | 3 |
| Net amount recognized | $ | 999 |
| | $ | 999 |
| | $ | (7 | ) | | $ | (3 | ) |
|
Components of net periodic cost (benefit) | The components of net periodic cost (benefit) are presented in the following table. | | | | | | | | | | | | | Years ended December 31 | | | | | | (In millions) | 2016 | | 2015 | | 2014 | Pension cost (benefit) | | | | | | Service cost | $ | — |
| | $ | 4 |
| | $ | 9 |
| Interest cost on projected benefit obligation | 113 |
| | 112 |
| | 132 |
| Expected return on plan assets | (160 | ) | | (174 | ) | | (191 | ) | Amortization of net actuarial loss | 37 |
| | 34 |
| | 25 |
| Settlement loss | — |
| | — |
| | 84 |
| Net periodic pension cost (benefit) | $ | (10 | ) | | $ | (24 | ) | | $ | 59 |
| | | | | | | Postretirement cost (benefit) | | | | | | Interest cost on projected benefit obligation | $ | — |
| | $ | 1 |
| | $ | 1 |
| Amortization of prior service credit | (2 | ) | | (3 | ) | | (10 | ) | Amortization of net actuarial loss | — |
| | 1 |
| | 1 |
| Curtailment gain | — |
|
| — |
|
| (86 | ) | Net periodic postretirement cost (benefit) | $ | (2 | ) | | $ | (1 | ) | | $ | (94 | ) |
|
Schedule of amounts recognized in Other comprehensive income | The amounts recognized in Other comprehensive income are presented in the following table. | | | | | | | | | | | | | Years ended December 31 | | | | | | (In millions) | 2016 | | 2015 | | 2014 | Pension and postretirement benefits | | | | | | Amounts arising during the period | $ | (29 | ) | | $ | (111 | ) | | $ | (337 | ) | Curtailment and other | — |
| | 56 |
| | (81 | ) | Settlement | — |
| | — |
| | 84 |
| Reclassification adjustment relating to prior service credit | (2 | ) | | (3 | ) | | (10 | ) | Reclassification adjustment relating to actuarial loss | 37 |
| | 35 |
| | 26 |
| Settlement through group annuity purchase | (2 | ) | | — |
| | — |
| Total increase (decrease) in Other comprehensive income | $ | 4 |
| | $ | (23 | ) | | $ | (318 | ) |
|
Schedule of estimated amounts to be recognized from Accumulated other comprehensive income into net periodic cost (benefit) during next fiscal year | The table below presents the estimated amounts to be recognized from AOCI into net periodic cost (benefit) during 2017. | | | | | | | | | (In millions) | Pension Benefits | | Postretirement Benefits | Amortization of prior service credit | $ | — |
| | $ | (2 | ) | Amortization of net actuarial loss | 36 |
| | — |
| Total estimated amounts to be recognized | $ | 36 |
| | $ | (2 | ) |
|
Actuarial assumptions for benefit obligations and for net cost or benefit | Actuarial assumptions used for the CNA Retirement Plan and CNA Health and Group Benefits Program to determine benefit obligations are presented in the following table. | | | | | | | December 31 | 2016 | | 2015 | Pension benefits | | | | Discount rate | 3.950 | % | | 4.150 | % | Expected long term rate of return | 7.500 |
| | 7.500 |
| Postretirement benefits | | | | Discount rate | 2.750 | % | | 2.750 | % |
Actuarial assumptions used for the CNA Retirement Plan and CNA Health and Group Benefits Program to determine net cost or benefit are presented in the following table. | | | | | | | | | | Years ended December 31 | 2016 | | 2015 | | 2014 | Pension benefits | | | | | | Discount rate | 4.150 | % | | 3.850%/4.000% |
| | 4.650 | % | Expected long term rate of return | 7.500 |
| | 7.500 |
| | 7.500 |
| Rate of compensation increases | N/A |
| | 3.920 |
| | 3.990 |
| Postretirement benefits | | | | | | Discount rate | 2.750 | % | | 2.500 | % | | 3.600%/3.100% |
|
|
Fair value of plan assets measured on a recurring basis | Pension plan assets measured at fair value on a recurring basis as well as cash are presented in the following tables. | | | | | | | | | | | | | | | | | | December 31, 2016 | | | | | | | | | (In millions) | | Level 1 | | Level 2 | | Level 3 | | Total | Assets | | | | | | | | | Fixed maturity securities: | | | | | | | | | Corporate and other bonds | | $ | — |
| | $ | 500 |
| | $ | 10 |
| | $ | 510 |
| States, municipalities and political subdivisions | | — |
| | 63 |
| | — |
| | 63 |
| Asset-backed: | | | | | | | | | Residential mortgage-backed | | — |
| | 109 |
| | — |
| | 109 |
| Commercial mortgage-backed | | — |
| | 66 |
| | — |
| | 66 |
| Other asset-backed | | — |
| | 4 |
| | — |
| | 4 |
| Total asset-backed | | — |
| | 179 |
| | — |
| | 179 |
| Total fixed maturity securities | | — |
| | 742 |
| | 10 |
| | 752 |
| Equity securities | | 363 |
| | 105 |
| | — |
| | 468 |
| Derivative financial instruments | | — |
| | — |
| | — |
| | — |
| Short term investments | | 11 |
| | 35 |
| | — |
| | 46 |
| Other assets | | — |
| | 37 |
| | — |
| | 37 |
| Cash | | 14 |
| | — |
| | — |
| | 14 |
| Total assets measured at fair value | | $ | 388 |
| | $ | 919 |
| | $ | 10 |
| | 1,317 |
| Total limited partnerships measured at net asset value (1) | | | | | | | | 876 |
| Total plan assets | | | | | | | | $ | 2,193 |
|
| | | | | | | | | | | | | | | | | | December 31, 2015 | | | | | | | | | (In millions) | | Level 1 | | Level 2 | | Level 3 | | Total Assets | Assets | | | | | | | | | Fixed maturity securities: | | | | | | | | | Corporate and other bonds | | $ | — |
| | $ | 455 |
| | $ | 10 |
| | $ | 465 |
| States, municipalities and political subdivisions | | — |
| | 106 |
| | — |
| | 106 |
| Asset-backed: | | | | | | | | | Residential mortgage-backed | | — |
| | 133 |
| | — |
| | 133 |
| Commercial mortgage-backed | | — |
| | 69 |
| | — |
| | 69 |
| Other asset-backed | | — |
| | 11 |
| | — |
| | 11 |
| Total asset-backed | | — |
| | 213 |
| | — |
| | 213 |
| Total fixed maturity securities | | — |
| | 774 |
| | 10 |
| | 784 |
| Equity securities | | 336 |
| | 107 |
| | — |
| | 443 |
| Derivative financial instruments | | 1 |
| | — |
| | — |
| | 1 |
| Short term investments | | 24 |
| | 28 |
| | — |
| | 52 |
| Other assets | | — |
| | 52 |
| | — |
| | 52 |
| Total assets measured at fair value | | $ | 361 |
| | $ | 961 |
| | $ | 10 |
| | 1,332 |
| Total limited partnerships measured at net asset value (1) | |
|
| |
|
| |
|
| | 935 |
| Total plan assets | |
| |
| |
| | $ | 2,267 |
|
(1) In accordance with Subtopic 820-10, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. |
Reconciliation of level 3 plan assets | The tables below present a reconciliation for all pension plan assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3). | | | | | | | | | | | | | | | | | | | | | | | | | Level 3 (In millions) | Balance as of January 1, 2016 | | Actual return on assets still held as of December 31, 2016 | | Actual return on assets sold during the year ended December 31, 2016 | | Purchases, sales and settlements | | Net transfers into (out of) Level 3 | | Balance as of December 31, 2016 | Fixed maturity securities: | | | | | | | | | | | | Corporate and other bonds | $ | 10 |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | 10 |
| Total | $ | 10 |
|
| $ | — |
|
| $ | — |
|
| $ | — |
|
| $ | — |
|
| $ | 10 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | Level 3 (In millions) | Balance as of January 1, 2015 | | Actual return on assets still held as of
December 31, 2015 | | Actual return on assets sold during the year ended December 31, 2015 | | Purchases, sales and settlements | | Net transfers into (out of) Level 3 | | Balance as of December 31, 2015 | Fixed maturity securities: | | | | | | | | | | | | Corporate and other bonds | $ | 15 |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | (5 | ) | | $ | 10 |
| Total | $ | 15 |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | (5 | ) | | $ | 10 |
|
|
Estimated future minimum benefit payments to participants | The table below presents the estimated future minimum benefit payments to participants as of December 31, 2016. | | | | | | | | | (In millions) | Pension Benefits | | Postretirement Benefits | 2017 | $ | 178 |
| | $ | 3 |
| 2018 | 178 |
| | 2 |
| 2019 | 177 |
| | 2 |
| 2020 | 178 |
| | 2 |
| 2021 | 178 |
| | 2 |
| 2022-2026 | 883 |
| | 3 |
|
|