Consolidated Statement of Comprehensive Income (loss) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net income (loss)	$ 1,483	$ 653
Other comprehensive income, net-of-tax:
Net change in available-for-sale debt and marketable equity securities	(906)	(924)
Net change in derivatives	172	382
Employee benefit plan adjustments	85	952
Net change in foreign currency translation adjustments	(42)	31
Other comprehensive income	(691)	441
Comprehensive income (loss)	$ 792	$ 1,094