CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities
Net income	$ 1,030	$ 1,220
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized capital gains	(20)	(7)
Stock-based compensation	68	53
Depreciation and amortization	238	225
(Benefit) provision for deferred income taxes	(6)	12
Changes in operating assets and liabilities, net of effect of businesses acquired:
Receivables	436	(77)
Other assets	(236)	(205)
Benefits payable	131	399
Other liabilities	121	392
Unearned revenues	(95)	1,820
Other, net	51	44
Net cash provided by operating activities	1,718	3,876
Cash flows from investing activities
Acquisitions, net of cash acquired	(288)	(14)
Purchases of property and equipment	(304)	(216)
Purchases of investment securities	(2,166)	(2,667)
Maturities of investment securities	1,111	1,129
Proceeds from sales of investment securities	894	625
Net cash used in investing activities	(753)	(1,143)
Cash flows from financing activities
Receipts (withdrawals) from contract deposits, net	(347)	225
Repayment of long-term debt	(36)	0
Change in book overdraft	(29)	(110)
Common stock repurchases	(513)	(541)
Dividends paid	(124)	(41)
Excess tax benefit from stock-based compensation	21	12
Proceeds from stock option exercises and other	49	68
Net cash used in financing activities	(979)	(387)
(Decrease) increase in cash and cash equivalents	(14)	2,346
Cash and cash equivalents at beginning of period	1,377	1,673
Cash and cash equivalents at end of period	1,363	4,019
Supplemental cash flow disclosures:
Interest payments	65	68
Income tax payments, net	$ 514	$ 718