CONSOLIDATED STATEMENT OF SHAREHOLDER'S EQUITY (USD $) In Millions	Total	Capital stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Retained earnings [Member]
Balance at Mar. 31, 2010	$ 5,273	$ 915	$ 1	$ 104	$ 4,253
Net income	570				570
Net unrealized gain on available-for-sale marketable securities, net of tax	3			3
Reclassification adjustment for net loss (net gain) included in net income, net of tax	(8)			(8)
Total comprehensive income	565			(5)	570
Balance at Jun. 30, 2010	5,838	915	1	99	4,823
Balance at Mar. 31, 2011	6,856	915	1	100	5,840
Net income	465				465
Net unrealized gain on available-for-sale marketable securities, net of tax	9			9
Reclassification adjustment for net loss (net gain) included in net income, net of tax	1			1
Total comprehensive income	475			10	465
Balance at Jun. 30, 2011	$ 7,331	$ 915	$ 1	$ 110	$ 6,305