Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net income	$ 1,352	$ 1,310	$ 1,188
Other comprehensive (loss) income, net of tax:
Unrecognized amounts on retirement benefits, net of tax of $(10), $29 and $(45)	(30)	54	(114)
Foreign currency translation adjustment	(10)	(106)	255
Unrealized (losses) gains on available-for-sale securities, net of tax of $(279), $(318) and $709	(419)	(480)	1,066
Unrealized (losses) gains on cash flow hedges, net of tax of $(5), $15 and $3	(8)	23	7
Total other comprehensive (loss) income, net of tax	(467)	(509)	1,214
Comprehensive income	885	801	2,402
Comprehensive income attributable to noncontrolling interests	21	72	31
Comprehensive income attributable to MEHC	$ 864	$ 729	$ 2,371