Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities
Net income		$ 684	$ 1,765
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on business held-for-sale		790	0
Net realized capital gains		(82)	(28)
Stock-based compensation		69	83
Depreciation		218	201
Other intangible amortization		51	36
(Benefit) provision for deferred income taxes		(304)	2
Changes in operating assets and liabilities, net of effect of businesses acquired and dispositions:
Receivables		(619)	(1,150)
Other assets		(1,658)	(545)
Benefits payable		410	275
Other liabilities		680	317
Unearned revenues		3,252	3,076
Other, net		70	67
Net cash provided by operating activities		3,561	4,099
Cash flows from investing activities
Acquisitions, net of cash acquired		(354)	(9)
Purchases of property and equipment, net		(272)	(233)
Purchases of investment securities		(2,624)	(3,208)
Maturities of investment securities		555	649
Proceeds from sales of investment securities		2,408	1,723
Net cash used in investing activities		(287)	(1,078)
Cash flows from financing activities
Receipts from contract deposits, net		1,515	2,081
Proceeds from issuance of senior notes, net		0	985
Proceeds (repayment) from issuance of commercial paper, net		243	(102)
Change in book overdraft		(67)	(95)
Common stock repurchases		(93)	(1,578)
Dividends paid		(126)	(104)
Proceeds from stock option exercises and other		43	54
Net cash provided by financing activities		1,515	1,241
Increase in cash and cash equivalents		4,789	4,262
Cash and cash equivalents at beginning of period		4,042	3,877
Cash and cash equivalents at end of period	[1]	8,831	8,139
Supplemental cash flow disclosures:
Interest payments		98	92
Income tax payments, net		$ 405	$ 694

[1] Includes $779 million of cash and cash equivalents classified as held-for-sale at June 30, 2018.