Income Taxes (Details) - USD ($)	3 Months Ended				9 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Income Tax [Line Items]
Income tax expense related to continuing operations	$ 204,000,000			$ 198,000,000	$ 704,000,000	$ 606,000,000
Net discrete tax expense (benefits)	$ (16,000,000)			$ 4,000,000	$ (45,000,000)	$ (14,000,000)
Income tax rate (as a percent)	24.10%			27.50%	27.30%	29.70%
Discrete tax benefit		$ 25,000,000
Unrecognized tax benefits	$ 564,000,000				$ 564,000,000
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	392,000,000				392,000,000
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit (up to)	123,000,000				123,000,000
Income tax expense	3,000,000			$ 5,000,000	9,000,000	$ 12,000,000
Accrued interest and penalties on unrecognized tax benefits	78,000,000				$ 78,000,000
CRA
Income Tax [Line Items]
Income tax benefit to settle transfer pricing			$ 12,000,000
Foreign Tax Authority
Income Tax [Line Items]
Net discrete tax expense (benefits)	$ (19,000,000)