Accounting Policies 1 (Details) (Notional Pooling Arrangement [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Notional Pooling Arrangement [Member]
Other indebtedness cash pooling arrangement
Total borrowing position outstanding at March 31, 2012	$ 139
Borrowings	253	154
Repayments	(247)	(86)
Foreign currency exchange effect	(5)
Total borrowing position outstanding at June 30, 2012	$ 140