| Segment Reporting [Abstract] | Period [Axis] |
|---|
2015-04-01 - 2016-03-31 |
|---|
Segment Reporting [Abstract] | |
Selected segment financial information | Selected Segment Financial Information | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Selected Operating Results Year Ended March 31, 2016 | | North America | | Europe | | Asia | | South America | | Eliminations and Other | | Total | Net sales - third party | | $ | 3,262 |
| | $ | 3,055 |
| | $ | 1,879 |
| | $ | 1,482 |
| | $ | 194 |
| | $ | 9,872 |
| Net sales - intersegment | | 4 |
| | 168 |
| | 113 |
| | 93 |
| | (378 | ) | | — |
| Net sales | | $ | 3,266 |
| | $ | 3,223 |
| | $ | 1,992 |
| | $ | 1,575 |
| | $ | (184 | ) | | $ | 9,872 |
| | | | | | | | | | | | | | Depreciation and amortization | | $ | 143 |
| | $ | 106 |
| | $ | 61 |
| | $ | 61 |
| | $ | (18 | ) | | $ | 353 |
| Income tax (benefit) provision | | $ | (53 | ) | | $ | (11 | ) | | $ | 12 |
| | $ | 81 |
| | $ | 17 |
| | $ | 46 |
| Capital expenditures | | $ | 143 |
| | $ | 146 |
| | $ | 35 |
| | $ | 39 |
| | $ | 7 |
| | $ | 370 |
| | | | | | | | | | | | | | March 31, 2016 | | | | | | | | | | | | | Investment in and advances to non–consolidated affiliates | | $ | — |
| | $ | 488 |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | 488 |
| Total assets | | $ | 2,370 |
| | $ | 2,687 |
| | $ | 1,516 |
| | $ | 1,584 |
| | $ | 153 |
| | $ | 8,310 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Selected Operating Results Year Ended March 31, 2015 | | North America | | Europe | | Asia | | South America | | Eliminations and Other | | Total | Net sales - third party | | $ | 3,465 |
| | $ | 3,609 |
| | $ | 2,139 |
| | $ | 1,749 |
| | $ | 185 |
| | $ | 11,147 |
| Net sales - intersegment | | 18 |
| | 174 |
| | 201 |
| | 101 |
| | (494 | ) | | — |
| Net sales | | $ | 3,483 |
| | $ | 3,783 |
| | $ | 2,340 |
| | $ | 1,850 |
| | $ | (309 | ) | | $ | 11,147 |
| | | | | | | | | | | | | | Depreciation and amortization | | $ | 137 |
| | $ | 103 |
| | $ | 71 |
| | $ | 63 |
| | $ | (22 | ) | | $ | 352 |
| Income tax (benefit) provision | | $ | (27 | ) | | $ | 12 |
| | $ | 16 |
| | $ | (1 | ) | | $ | 14 |
| | $ | 14 |
| Capital expenditures | | $ | 122 |
| | $ | 257 |
| | $ | 85 |
| | $ | 53 |
| | $ | 1 |
| | $ | 518 |
| | | | | | | | | | | | | | March 31, 2015 | | | | | | | | | | | | | Investment in and advances to non–consolidated affiliates | | $ | — |
| | $ | 447 |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | 447 |
| Total assets | | $ | 2,744 |
| | $ | 2,952 |
| | $ | 1,663 |
| | $ | 1,588 |
| | $ | 155 |
| | $ | 9,102 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Selected Operating Results Year Ended March 31, 2014 | | North America | | Europe | | Asia | | South America | | Eliminations and Other | | Total | Net sales - third party | | $ | 3,042 |
| | $ | 3,145 |
| | $ | 1,849 |
| | $ | 1,543 |
| | $ | 188 |
| | $ | 9,767 |
| Net sales - intersegment | | 8 |
| | 135 |
| | 27 |
| | 45 |
| | (215 | ) | | — |
| Net sales | | $ | 3,050 |
| | $ | 3,280 |
| | $ | 1,876 |
| | $ | 1,588 |
| | $ | (27 | ) | | $ | 9,767 |
| | | | | | | | | | | | | | Depreciation and amortization | | $ | 126 |
| | $ | 103 |
| | $ | 68 |
| | $ | 69 |
| | $ | (32 | ) | | $ | 334 |
| Income tax provision | | $ | (34 | ) | | $ | 6 |
| | $ | 16 |
| | $ | 6 |
| | $ | 17 |
| | $ | 11 |
| Capital expenditures | | $ | 147 |
| | $ | 241 |
| | $ | 198 |
| | $ | 117 |
| | $ | 14 |
| | $ | 717 |
|
|
Reconciliation from income from reportable segments to net income attributable to out common shareholder | The following table shows the reconciliation from income from reportable segments to “Net income attributable to our common shareholder” (in millions). | | | | | | | | | | | | | | | | Year Ended March 31, | | | 2016 | | 2015 | | 2014 | North America | | $ | 258 |
| | $ | 273 |
| | $ | 229 |
| Europe | | 116 |
| | 250 |
| | 265 |
| Asia | | 135 |
| | 141 |
| | 160 |
| South America | | 282 |
| | 240 |
| | 231 |
| Intersegment eliminations | | — |
| | (2 | ) | | — |
| Depreciation and amortization | | (353 | ) | | (352 | ) | | (334 | ) | Interest expense and amortization of debt issuance costs | | (327 | ) | | (326 | ) | | (304 | ) | Adjustment to eliminate proportional consolidation | | (30 | ) | | (33 | ) | | (40 | ) | Unrealized losses on change in fair value of derivative instruments, net | | (4 | ) | | — |
| | (10 | ) | Realized (losses) gains on derivative instruments not included in segment income | | (1 | ) | | (6 | ) | | 5 |
| Gain on assets held for sale | | — |
| | 22 |
| | 6 |
| Loss on extinguishment of debt | | (13 | ) | | — |
| | — |
| Restructuring and impairment, net | | (48 | ) | | (37 | ) | | (75 | ) | Loss on sale of fixed assets | | (4 | ) | | (5 | ) | | (9 | ) | Other costs, net | | (3 | ) | | (3 | ) | | (9 | ) | Income before income taxes | | 8 |
| | 162 |
| | 115 |
| Income tax provision | | 46 |
| | 14 |
| | 11 |
| Net (loss) income | | (38 | ) | | 148 |
| | 104 |
| Net income attributable to noncontrolling interests | | — |
| | — |
| | — |
| Net (loss) income attributable to our common shareholder | | $ | (38 | ) | | $ | 148 |
| | $ | 104 |
|
|
Schedule of revenue from external customers attributed to foreign countries by geographic area | The tables below present “Net sales” and “Long-lived assets and other intangible assets” by geographical area (in millions). “Net sales” are attributed to geographical areas based on the origin of the sale. “Long-lived assets and other intangible assets” are attributed to geographical areas based on asset location and exclude investments in and advances to our non-consolidated affiliates and goodwill. | | | | | | | | | | | | | | | | Year Ended March 31, | | | 2016 | | 2015 | | 2014 | Net sales: | | | | | | | United States | | $ | 3,334 |
| | $ | 3,507 |
| | $ | 3,021 |
| Asia and Other Pacific | | 1,879 |
| | 2,139 |
| | 1,845 |
| Brazil | | 1,482 |
| | 1,750 |
| | 1,544 |
| Canada | | 121 |
| | 144 |
| | 209 |
| Germany | | 2,506 |
| | 2,976 |
| | 2,449 |
| Other Europe | | 550 |
| | 631 |
| | 699 |
| Total Net sales | | $ | 9,872 |
| | $ | 11,147 |
| | $ | 9,767 |
|
|
Schedule of disclosure on geographic areas, long-lived assets in individual foreign countries by country | | | | | | | | | | | | | March 31, | | | 2016 | | 2015 | Long-lived assets and other intangibles: | | | | | United States | | $ | 1,483 |
| | $ | 1,518 |
| Asia and Other Pacific | | 784 |
| | 840 |
| Brazil | | 840 |
| | 866 |
| Canada | | 70 |
| | 78 |
| Germany | | 287 |
| | 251 |
| United Kingdom | | 43 |
| | 45 |
| Other Europe | | 522 |
| | 528 |
| Total long-lived assets | | $ | 4,029 |
| | $ | 4,126 |
|
|
Net sales to largest customers, as a percentage of total net sales | The table below shows our net sales to Rexam Plc (Rexam) and Affiliates of Ball Corporation (Ball Corporation), our two largest customers, as a percentage of total “Net sales.” | | | | | | | | | | | | | Year Ended March 31, | | | 2016 | | 2015 | | 2014 | Rexam (A) | | 19 | % | | 18 | % | | 17 | % | Ball Corporation (A) | | 11 | % | | 10 | % | | 10 | % |
| | (A) | In February of 2015, Ball Corporation made an offer to acquire Rexam. This acquisition will be subject to regulatory and shareholder approval. |
|
Percentage of total combined metal purchases | The table below shows our purchases from RT as a percentage of our total combined metal purchases. | | | | | | | | | | | | | Year Ended March 31, | | | 2016 | | 2015 | | 2014 | Purchases from RT as a percentage of total combined metal purchases | | 12 | % | | 15 | % | | 17 | % |
|