Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income	$ 1,940	$ 1,037
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash items	358	285
Realized capital gains and losses	(318)	92
Gain on disposition of operations	(15)	(4)
Interest credited to contractholder funds	522	558
Changes in:
Policy benefits and other insurance reserves	1,276	978
Unearned premiums	525	540
Deferred policy acquisition costs	(176)	(159)
Premium installment receivables, net	(267)	(236)
Reinsurance recoverables, net	(1,017)	(420)
Income taxes	119	30
Other operating assets and liabilities	267	41
Net cash provided by operating activities	3,214	2,742
Proceeds from sales
Fixed income securities	19,508	19,132
Equity securities	5,179	4,069
Limited partnership interests	767	634
Other investments	170	206
Investment collections
Fixed income securities	3,038	3,430
Mortgage loans	477	403
Other investments	458	281
Investment purchases
Fixed income securities	(23,935)	(22,282)
Equity securities	(5,296)	(4,113)
Limited partnership interests	(1,082)	(1,128)
Mortgage loans	(311)	(460)
Other investments	(700)	(674)
Change in short-term investments, net	2,257	94
Change in other investments, net	(28)	(60)
Purchases of property and equipment, net	(216)	(190)
Acquisition of operations	(1,356)	0
Net cash used in investing activities	(1,070)	(658)
Cash flows from financing activities
Repayments of long-term debt	0	(16)
Contractholder fund deposits	767	785
Contractholder fund withdrawals	(1,416)	(1,537)
Dividends paid on common stock	(391)	(364)
Dividends paid on preferred stock	(87)	(87)
Treasury stock purchases	(848)	(1,154)
Shares reissued under equity incentive plans, net	132	123
Excess tax benefits on share-based payment arrangements	0	25
Other	(47)	35
Net cash used in financing activities	(1,890)	(2,190)
Net increase (decrease) in cash	254	(106)
Cash at beginning of period	436	495
Cash at end of period	$ 690	$ 389