Consolidated Statements of Operations (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Operations [Abstract]
Tax benefit (expense) on unrealized (gain) loss on marketable securities and cash flow hedges	$ 2	$ 0	$ (23)
Tax benefit (expense) on unamortized benefit plan costs	$ 823	$ (183)	$ (374)