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
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Change in unrealized holding gains on investments, tax expense	$ 12	$ 22	$ 53	$ 26
Reclassification adjustment for gross gains included in net income, tax expense	6	12	8	19
Unrealized gains transferred to noncontrolling interest on sale of life affiliate, tax expense	$ 0	$ 0	$ 0	$ 4