| Component: (Network and Table) | |
|---|---|
| Network | 1118 - Disclosure - Pension and Postretirement Benefits - Pension Benefit Payments Expected to be Paid (Detail) (http://www.anico.com/taxonomy/role/DisclosurePensionAndPostretirementBenefitsPensionBenefitPaymentsExpectedToBePaid) |
| Table | (Implied) |
| Reporting Entity [Axis] | 0000904163 (http://www.sec.gov/CIK) |
| Compensation and Retirement Disclosure [Abstract] | Period [Axis] |
|---|---|
2016-12-31 | |
Compensation and Retirement Disclosure [Abstract] | |
2017 | |
2018 | |
2019 | |
2020 | |
2021 | |
2022-2026 |