Income Taxes (Details Textual) (USD $)	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Details [Line Items]
Increase in income tax provision related to tax losses	$ 95,000,000	$ 94,000,000	$ 84,000,000
Impact on income tax provision of the credits	22,000,000	38,000,000	8,000,000
Income tax holiday, amount	9,000,000
Deferred tax assets, valuation allowance	(528,000,000)	(426,000,000)
Net operating loss carryforwards	515,000,000
Tax credit carryforward	112,000,000	97,000,000
Operating loss carryforwards, valuation allowance	381,000,000	287,000,000
Tax credit carryforward, valuation allowance	99,000,000	84,000,000
Operating loss carryforwards		396,000,000
Undistributed earnings of foreign subsidiaries (outside Canada)	2,000,000,000
Unrecognized tax benefits	37,000,000	39,000,000	30,000,000	28,000,000
Maximum amount by which reserves for interest and penalties for unrecognized tax benefits may decrease in the next 12 months	13,000,000
Accrued income tax penalties and interest	5,000,000	4,000,000	3,000,000
Income tax penalties and interest expense	1,000,000	1,000,000
Settlement with taxing authorities including interest			(8,000,000)
Taxes payable	14,000,000	52,000,000
Taxes payable, current	11,000,000	31,000,000
Deferred Tax Assets, Other [Member]
Income Tax Details [Line Items]
Deferred tax assets, valuation allowance	(48,000,000)	(55,000,000)
New York [Member]
Income Tax Details [Line Items]
Income tax credits and adjustments	8,000,000
United Kingdom [Member]
Income Tax Details [Line Items]
Income tax credits and adjustments	11,000,000
Canada [Member]
Income Tax Details [Line Items]
Deferred tax assets, valuation allowance	(446,000,000)
Tax credit carryforward	46,000,000
Operating loss carryforwards	$ 357,000,000