Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Unrecognized amounts on retirement benefits, tax	$ 5	$ 2	$ 3	$ 0
Unrealized losses on available-for-sale securities, tax	(83)	(53)	(24)	(180)
Unrealized gains (losses) on cash flow hedges, tax	$ 9	$ 7	$ (2)	$ 8