CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net income	$ 1,877	$ 2,171	$ 2,850
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash items	382	371	366
Realized capital gains and losses	90	(30)	(694)
Loss on extinguishment of debt	0	0	1
(Gain) loss on disposition of operations	(5)	(3)	74
Interest credited to contractholder funds	726	761	919
Changes in:
Policy benefits and other insurance reserves	631	473	541
Unearned premiums	362	638	766
Deferred policy acquisition costs	(165)	(239)	(220)
Premium installment receivables, net	(42)	(134)	(257)
Reinsurance recoverables, net	(264)	(178)	(1,068)
Income taxes	417	(119)	205
Other operating assets and liabilities	(16)	(95)	(247)
Net cash provided by operating activities	3,993	3,616	3,236
Proceeds from sales
Fixed income securities	25,061	28,693	34,609
Equity securities	5,546	3,754	6,755
Limited partnership interests	881	1,101	1,473
Mortgage loans	0	6	10
Other investments	262	545	406
Investment collections
Fixed income securities	4,533	4,432	3,736
Mortgage loans	501	538	1,106
Other investments	421	293	191
Investment purchases
Fixed income securities	(27,990)	(30,758)	(38,759)
Equity securities	(5,950)	(4,960)	(5,443)
Limited partnership interests	(1,450)	(1,343)	(1,398)
Mortgage loans	(646)	(687)	(501)
Other investments	(885)	(902)	(972)
Change in short-term investments, net	(2,446)	385	272
Change in other investments, net	(51)	(52)	46
Purchases of property and equipment, net	(313)	(303)	(288)
Disposition (acquisition) of operations	0	0	378
Net cash (used in) provided by investing activities	(2,526)	742	1,621
Cash flows from financing activities
Proceeds from issuance of long-term debt	1,236	0	0
Repayments of long-term debt	(17)	(20)	(1,006)
Proceeds from issuance of preferred stock	0	0	965
Contractholder fund deposits	1,049	1,052	1,184
Contractholder fund withdrawals	(2,087)	(2,327)	(3,446)
Dividends paid on common stock	(486)	(483)	(477)
Dividends paid on preferred stock	(116)	(116)	(87)
Treasury stock purchases	(1,337)	(2,808)	(2,301)
Shares reissued under equity incentive plans, net	164	130	266
Excess tax benefits on share-based payment arrangements	32	45	41
Other	36	7	(14)
Net cash used in financing activities	(1,526)	(4,520)	(4,875)
Net decrease in cash	(59)	(162)	(18)
Cash at beginning of year	495	657	675
Cash at end of year	$ 436	$ 495	$ 657