Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net income	$ 2,690	$ 2,366
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized (gains) losses on financial instruments	(89)	22
Other-than-temporary impairment losses recognized in income	17	12
(Gain) loss on extinguishment of debt	(1)	18
Deferred income taxes	79	2
Amortization, net of accretion	515	495
Depreciation expense	71	61
Share-based compensation	140	78
Changes in operating assets and liabilities:
Receivables, net	(589)	(570)
Other invested assets	(28)	(11)
Other assets	(258)	(445)
Policy liabilities	1,251	(610)
Unearned income	(2)	1,158
Accounts payable and accrued expenses	(1,015)	29
Other liabilities	632	70
Income taxes	(286)	187
Other, net	(60)	(105)
Net cash provided by operating activities	3,067	2,757
Investing activities
Purchases of fixed maturity securities	(5,023)	(4,886)
Proceeds from fixed maturity securities:
Sales	2,560	3,865
Maturities, calls and redemptions	894	1,017
Purchases of equity securities	(5,974)	(658)
Proceeds from sales of equity securities	6,059	1,777
Purchases of other invested assets	(116)	(247)
Proceeds from sales of other invested assets	216	198
Changes in securities lending collateral	40	(170)
Purchases of subsidiaries, net of cash acquired	0	(1,722)
Purchases of property and equipment	(455)	(533)
Other, net	(18)	15
Net cash used in investing activities	(1,817)	(1,344)
Financing activities
Net proceeds from (repayments of) commercial paper borrowings	203	(704)
Proceeds from long-term borrowings	0	835
Repayments of long-term borrowings	(73)	(663)
Proceeds from short-term borrowings	4,805	3,330
Repayments of short-term borrowings	(4,940)	(3,485)
Changes in securities lending payable	(40)	170
Changes in bank overdrafts	84	69
Premiums paid on equity call options	(1)	0
Proceeds from issuance of common stock under Equity Units stock purchase contracts	0	1,250
Repurchase and retirement of common stock	(752)	(795)
Change in collateral and settlements of debt-related derivatives	0	22
Cash dividends	(412)	(388)
Proceeds from issuance of common stock under employee stock plans	100	95
Taxes paid through withholding of common stock under employee stock plans	(80)	(76)
Net cash used in financing activities	(1,106)	(340)
Change in cash and cash equivalents	144	1,073
Cash and cash equivalents at beginning of period	3,934	3,609
Cash and cash equivalents at end of period	$ 4,078	$ 4,682