Stockholders' Equity (Changes in Accumulated Other Comprehensive Income (Loss) by Component) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Beginning balance	$ (3)
Other Comprehensive Income (Loss), Net of Tax	98	(53)
Ending balance	107
Foreign Currency Translation Adjustments, Net of Tax
Beginning balance	168
Other comprehensive income (loss) before reclassifications	110
Amounts reclassified to earnings and other	0
Other Comprehensive Income (Loss), Net of Tax	110
Ending balance	278
Unrealized Losses on Cash Flow Hedges, Net of Tax
Beginning balance	(11)
Other comprehensive income (loss) before reclassifications	(2)
Amounts reclassified to earnings and other	0
Other Comprehensive Income (Loss), Net of Tax	(2)
Ending balance	(13)
Unrealized Net Loss and Other Components of Benefit Plans, Net of Tax
Beginning balance	(160)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified to earnings and other	2
Other Comprehensive Income (Loss), Net of Tax	2
Ending balance	(158)
Parent Company [Member]
Beginning balance	(3)
Other comprehensive income (loss) before reclassifications	108
Amounts reclassified to earnings and other	2
Other Comprehensive Income (Loss), Net of Tax	110
Ending balance	$ 107