Condensed Consolidated Statements Of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities
Net income	$ 430	$ 368
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized capital gains	(9)	(1)
Stock-based compensation	44	33
Depreciation	88	79
Other intangible amortization	26	28
Benefit for deferred income taxes	(58)	(26)
Changes in operating assets and liabilities, net of effect of businesses acquired and dispositions:
Receivables	(644)	(524)
Other assets	(1,145)	(566)
Benefits payable	289	539
Other liabilities	1,051	684
Unearned revenues	17	57
Other, net	18	0
Net cash provided by operating activities	107	671
Cash flows from investing activities
Acquisitions, net of cash acquired	0	(6)
Proceeds from sale of business	0	72
Purchases of property and equipment	(123)	(106)
Purchases of investment securities	(829)	(507)
Maturities of investment securities	330	258
Proceeds from sales of investment securities	528	118
Net cash used in investing activities	(94)	(171)
Cash flows from financing activities
Receipts (withdrawals) from contract deposits, net	123	220
Change in book overdraft	(46)	(136)
Common stock repurchases	(66)	(49)
Dividends paid	(44)	(44)
Excess tax benefit from stock-based compensation	13	8
Proceeds from stock option exercises and other	18	25
Net cash (used in) provided by financing activities	(2)	24
Increase in cash and cash equivalents	11	524
Cash and cash equivalents at beginning of period	1,935	1,138
Cash and cash equivalents at end of period	1,946	1,662
Supplemental cash flow disclosures:
Interest payments	9	10
Income tax payments, net	$ 26	$ 12