Stockholders' Equity (Other Comprehensive Income (Loss), Net of Tax) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Stockholders' Equity Attributable to Parent [Abstract]
Foreign currency translation adjustments arising during period, net of income tax expense (benefit) of ($2), ($2), nil and $2	$ 56		$ 71		$ (5)		$ 30
Reclassified to income statement, net of income tax expense of $24, nil, $24 and nil (1)	44	[1]	0	[1]	44	[1]	0	[1]
Foreign currency translation adjustments, net of income tax expense (benefit) of $22, ($2), $24 and $2	100		71		39		30
Unrealized gains (losses) on cash flow hedges arising during period, net of income tax expense of nil, nil, nil and nil	(2)		2		(1)		2
Amortization of actuarial loss, prior service cost and transition obligation, net of income tax expense of $2, $2, $6 and $5 (2)	6	[2]	4	[2]	13	[2]	9	[2]
Foreign currency translation adjustments, net of income tax expense of nil, nil, nil and nil	(3)		(1)		(3)		0
Reclassified to income statement, net of income tax expense of $1, nil, $1 and nil	1		0		1		0
Retirement-related benefit plans, net of income tax expense of $3, $2, $7 and $5	4		3		11		9
Other Comprehensive Income, net of tax	$ 102		$ 76		$ 49		$ 41

[1] As a result of our sale of our 49% equity interest in Nadro, foreign currency translation net losses of $44 million were reclassified from AOCI to other income, within our condensed consolidated statement of operations. Such losses were previously considered in our impairment evaluation of the investment when we committed to a plan to sell the investment during the fourth quarter of 2013, and accordingly did not impact earnings for the second quarter and first six months of 2014.

[2] Pre-tax amount was reclassified into cost of sales and operating expenses in the condensed consolidated statements of operations. The related tax expense (benefit) was reclassified into income tax expense in the condensed consolidated statements of operations.