Consolidated Statement of Shareholder's Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings/ (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss) (AOCI)	Non-controlling Interests
Balance at Mar. 31, 2012	$ 123	$ 0	$ 1,659	$ (1,379)	$ (191)	$ 34
Balance, shares at Mar. 31, 2012		1,000
Increase (Decrease) in Stockholder's Equity [Roll Forward]
Net income	202			202
Net income attributable to noncontrolling interests	(1)					(1)
Currency translation adjustment, net of tax provision of $ — included in AOCI	(53)				(53)
Change in fair value of effective portion of hedges, net of tax/benefit included in AOCI	5				5
Change in pension and other benefits, net of tax included in AOCI	(29)				(29)
Acquisition of noncontrolling interest in Novelis Korea Ltd.	(9)		(5)		0	(4)
Noncontrolling interests cash dividends declared	(1)					(1)
Balance at Mar. 31, 2013	239	0	1,654	(1,177)	(268)	30
Balance, shares at Mar. 31, 2013		1,000
Increase (Decrease) in Stockholder's Equity [Roll Forward]
Net income	104			104
Net income attributable to noncontrolling interests	0
Currency translation adjustment, net of tax provision of $ — included in AOCI	120				122	(2)
Change in fair value of effective portion of hedges, net of tax/benefit included in AOCI	(18)				(18)	0
Change in pension and other benefits, net of tax included in AOCI	73				73
Return of capital	(250)		(250)
Balance at Mar. 31, 2014	268	0	1,404	(1,073)	(91)	28
Balance, shares at Mar. 31, 2014		1,000
Increase (Decrease) in Stockholder's Equity [Roll Forward]
Net income	148			148
Net income attributable to noncontrolling interests	0
Currency translation adjustment, net of tax provision of $ — included in AOCI	(304)				(302)	(2)
Change in fair value of effective portion of hedges, net of tax/benefit included in AOCI	(43)				(43)
Change in pension and other benefits, net of tax included in AOCI	(138)				(125)	(13)
Noncontrolling interests cash dividends declared	(1)					(1)
Balance at Mar. 31, 2015	$ (70)	$ 0	$ 1,404	$ (925)	$ (561)	$ 12
Balance, shares at Mar. 31, 2015		1,000