Segment Information 2 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenue from the United States and international locations
Total revenue	$ 1,152	$ 1,200	$ 2,297	$ 2,363
United States [Member]
Revenue from the United States and international locations
Total revenue	685	690	1,368	1,362
Europe [Member]
Revenue from the United States and international locations
Total revenue	266	302	538	600
Other [Member]
Revenue from the United States and international locations
Total revenue	$ 201	$ 208	$ 391	$ 401