Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net sales	$ 9,591	$ 9,872	$ 11,147
Cost of goods sold (exclusive of depreciation and amortization)	8,016	8,727	9,793
Selling, general and administrative expenses	421	407	427
Depreciation and amortization	360	353	352
Interest expense and amortization of debt issuance costs	294	327	326
Research and development expenses	58	54	50
Gain on assets held for sale	2	0	22
Loss on extinguishment of debt	134	13	0
Restructuring and impairment, net	10	48	37
Equity in net loss of non-consolidated affiliates	8	3	5
Other expense (income), net	95	(68)	17
Total expenses	9,394	9,864	10,985
Income before income taxes	197	8	162
Income tax provision	151	46	14
Net income (loss)	46	(38)	148
Net income attributable to noncontrolling interests	1	0	0
Net income (loss) attributable to our common shareholder	$ 45	$ (38)	$ 148