Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities
Net income	$ 234	$ 430
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized capital gains	(20)	(9)
Stock-based compensation	23	44
Depreciation	94	88
Other intangible amortization	21	26
Provision (benefit) for deferred income taxes	15	(58)
Changes in operating assets and liabilities, net of effect of businesses acquired and dispositions:
Receivables	(576)	(644)
Other assets	(685)	(1,145)
Benefits payable	138	289
Other liabilities	1,210	1,051
Unearned revenues	(4)	17
Other, net	32	18
Net cash provided by operating activities	482	107
Cash flows from investing activities
Purchases of property and equipment	(125)	(123)
Purchases of investment securities	(1,430)	(829)
Maturities of investment securities	213	330
Proceeds from sales of investment securities	914	528
Net cash used in investing activities	(428)	(94)
Cash flows from financing activities
Receipts (withdrawals) from contract deposits, net	318	123
Change in book overdraft	(44)	(46)
Common stock repurchases	(71)	(66)
Dividends paid	(47)	(44)
Excess tax benefit from stock-based compensation	20	13
Proceeds from stock option exercises and other	0	18
Net cash provided by (used in) financing activities	176	(2)
Increase in cash and cash equivalents	230	11
Cash and cash equivalents at beginning of period	2,571	1,935
Cash and cash equivalents at end of period	2,801	1,946
Supplemental cash flow disclosures:
Interest payments	10	9
Income tax payments, net	$ 5	$ 26