Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities
Net Income	$ 5,120		$ 2,646	$ 2,232
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	3,651		695	566
Realized investment (gains) losses	(177)		81	(237)
Deferred income taxes (benefits)	(313)		(101)	242
Debt extinguishment costs	2		0	321
Net changes in assets and liabilities, net of non-operating effects:
Accounts receivable	(713)		705	(233)
Inventories	149		(107)	(72)
Deferred policy acquisition costs	(242)		(237)	(282)
Reinsurance recoverables and other assets	(277)		(234)	115
Insurance liabilities	575		560	506
Pharmacy and service costs payable	(192)		(842)	35
Accounts payable, accrued expenses and other liabilities	1,343		332	696
Other, net	559		272	197
Net cash provided by (used in) operating activities	9,485		3,770	4,086
Proceeds from investments sold:
Debt securities and equity securities	3,487		2,655	2,012
Investment maturities and repayments:
Debt securities and equity securities	1,825		2,151	2,051
Commercial mortgage loans	199		215	335
Other sales, maturities and repayments (primarily short-term and other long-term investments)	1,311		734	1,702
Investments purchased or originated:
Debt securities and equity securities	(4,282)		(5,637)	(5,628)
Commercial mortgage loans	(307)		(312)	(430)
Other (primarily short-term and other long-term investments)	(1,753)		(1,189)	(1,065)
Property and equipment purchases	(1,050)		(528)	(471)
Acquisitions, net of cash acquired	(153)		(24,455)	(209)
Other, net	(11)		(12)	0
Net cash provided by (used in) investing activities	(734)		(26,378)	(1,703)
Cash Flows from Financing Activities
Deposits and interest credited to contractholder deposit funds	955		1,040	1,230
Withdrawals and benefit payments from contractholder deposit funds	(1,097)		(1,151)	(1,363)
Net change in short-term debt	(681)		1,487	80
Payments for debt extinguishment	(3)		0	(313)
Repayment of long-term debt	(4,491)		(131)	(1,250)
Net proceeds on issuance of long-term debt	0		22,856	1,581
Repurchase of common stock	(1,987)		(342)	(2,725)
Issuance of common stock	224		68	131
Other, net	(107)		(312)	(22)
Net cash provided by (used in) financing activities	(7,187)		23,515	(2,651)
Effect of foreign currency rate changes on cash and cash equivalents	(8)		(24)	55
Net increase (decrease) in cash, cash equivalents and restricted cash	1,556		883	(213)
Cash, cash equivalents and restricted cash, January 1,	3,855		2,972	3,185
Cash, cash equivalents and restricted cash, ending balance	5,411		3,855	2,972
Cash reclassified to assets held for sale	(743)		0	0
Cash, cash equivalents, and restricted cash per Consolidated Balance Sheets	4,668	[1]	3,855	2,972
Supplemental Disclosure of Cash Information:
Income taxes paid, net of refunds	1,776		1,019	1,036
Interest paid	$ 1,645		$ 267	$ 240

[1] Includes restricted cash of $26 million reported in Other noncurrent assets and $23 million reported in Long-term investments as of December 31, 2019.