Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income tax effect - unrecognized amounts on retirement benefits	$ 7	$ (28)	$ (10)
Income tax effect - unrealized gains (losses) on available-for-sale securities	178	79	(279)
Income tax effect - unrealized gains (losses) on cash flow hedges	$ 10	$ 5	$ (5)