CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities
Net income	$ 604	$ 775
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized capital gains	(14)	(5)
Stock-based compensation	54	41
Depreciation and amortization	160	151
(Benefit) provision for deferred income taxes	(9)	21
Changes in operating assets and liabilities, net of effect of businesses acquired:
Receivables	177	(587)
Other assets	(250)	(175)
Benefits payable	170	484
Other liabilities	51	202
Unearned revenues	2,077	20
Other, net	32	30
Net cash provided by operating activities	3,052	957
Cash flows from investing activities
Acquisitions, net of cash acquired	(76)	(11)
Purchases of property and equipment	(185)	(129)
Purchases of investment securities	(1,364)	(1,902)
Maturities of investment securities	757	751
Proceeds from sales of investment securities	529	432
Net cash used in investing activities	(339)	(859)
Cash flows from financing activities
Receipts (withdrawals) from contract deposits, net	152	188
Repayment of long-term debt	(36)	0
Change in book overdraft	(46)	(192)
Common stock repurchases	(278)	(301)
Dividends paid	(82)	0
Excess tax benefit from stock-based compensation	21	11
Proceeds from stock option exercises and other	48	91
Net cash used in financing activities	(221)	(203)
Increase (decrease) in cash and cash equivalents	2,492	(105)
Cash and cash equivalents at beginning of period	1,377	1,673
Cash and cash equivalents at end of period	3,869	1,568
Supplemental cash flow disclosures:
Interest payments	55	57
Income tax payments, net	$ 293	$ 407