Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income	$ 5,576	$ 4,847	$ 2,160
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash items	686	647	511
Realized capital gains (losses)	(1,356)	(1,885)	877
Pension and other postretirement remeasurement (gains) losses	(51)	114	468
Gain on disposition of operations	(4)	(6)	(6)
Interest credited to contractholder funds	638	640	654
Impairment of purchased intangibles	0	106	0
Changes in:
Policy benefits and other insurance reserves	(682)	(508)	469
Unearned premiums	598	801	915
Deferred policy acquisition costs	(125)	(85)	(296)
Premium installment receivables, net	(3)	(299)	(396)
Reinsurance recoverables, net	(11)	320	(656)
Income taxes	(232)	487	(380)
Other operating assets and liabilities	457	(50)	855
Net cash provided by operating activities	5,491	5,129	5,175
Proceeds from sales
Fixed income securities	31,950	29,849	33,183
Equity securities	8,405	5,277	6,859
Limited partnership interests	1,350	756	764
Mortgage loans	230	0	0
Other investments	340	303	533
Investment collections
Fixed income securities	2,235	2,570	3,466
Mortgage loans	626	695	529
Other investments	209	254	488
Investment purchases
Fixed income securities	(38,121)	(31,317)	(36,960)
Equity securities	(4,648)	(7,176)	(5,936)
Limited partnership interests	(1,265)	(1,332)	(1,679)
Mortgage loans	(203)	(844)	(664)
Other investments	(371)	(666)	(864)
Change in short-term and other investments, net	(3,871)	(725)	(603)
Purchases of property and equipment, net	(308)	(433)	(277)
Acquisition of operations	1	(18)	(558)
Net cash used in investing activities	(3,441)	(2,807)	(1,719)
Cash flows from financing activities
Proceeds from issuance of long-term debt	1,189	491	498
Redemption and repayment of long-term debt	0	(317)	(400)
Proceeds from issuance of preferred stock	0	1,414	557
Redemption of preferred stock	(288)	(1,132)	(385)
Contractholder fund deposits	991	996	1,010
Contractholder fund withdrawals	(1,494)	(1,662)	(1,967)
Dividends paid on common stock	(668)	(653)	(614)
Dividends paid on preferred stock	(108)	(134)	(134)
Treasury stock purchases	(1,737)	(1,735)	(2,303)
Shares reissued under equity incentive plans, net	63	120	73
Other	41	129	91
Net cash used in financing activities	(2,011)	(2,483)	(3,574)
Net increase (decrease) in cash	39	(161)	(118)
Cash at beginning of year	338	499	617
Cash at end of year	$ 377	$ 338	$ 499