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		$ 8,489	$ 5,120		$ 2,646
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		2,802	3,651		695
Realized investment losses (gains), net		(149)	(177)		81
Deferred income tax (benefit)		(386)	(313)		(101)
Gain on sale of business		(4,203)	0		0
Debt extinguishment costs		199	2		0
Net changes in assets and liabilities, net of non-operating effects:
Accounts receivable		(1,496)	(713)		705
Inventories		(504)	149		(107)
Deferred policy acquisition costs		(307)	(242)		(237)
Reinsurance recoverable and Other assets		230	(277)		(234)
Insurance liabilities		841	575		560
Pharmacy and other service costs payable		2,891	(192)		(842)
Accounts payable and Accrued expenses and other liabilities		1,346	1,343		332
Other, net		597	559		272
NET CASH PROVIDED BY OPERATING ACTIVITIES		10,350	9,485		3,770
Proceeds from investments sold:
Debt securities and equity securities		2,283	3,487		2,655
Investment maturities and repayments:
Debt securities and equity securities		1,519	1,825		2,151
Commercial mortgage loans		19	199		215
Other sales, maturities and repayments (primarily short-term and other long-term investments)		1,575	1,311		734
Investments purchased or originated:
Debt securities and equity securities		(4,765)	(4,282)		(5,637)
Commercial mortgage loans		(113)	(307)		(312)
Other (primarily short-term and other long-term investments)		(1,924)	(1,753)		(1,189)
Property and equipment purchases, net		(1,094)	(1,050)		(528)
Acquisitions, net of cash acquired		(139)	(153)		(24,455)
Divestiture, net of cash sold		5,592	0		0
Other, net		23	(11)		(12)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES		2,976	(734)		(26,378)
Cash Flows from Financing Activities
Deposits and interest credited to contractholder deposit funds		1,023	955		1,040
Withdrawals and benefit payments from contractholder deposit funds		(979)	(1,097)		(1,151)
Net change in short-term debt		60	(681)		1,487
Net proceeds on issuance of term loan		1,398	0		0
Repayment of term loan		(1,400)	0		0
Payments for debt extinguishment		(212)	(3)		0
Repayment of long-term debt		(8,047)	(4,491)		(131)
Net proceeds on issuance of long-term debt		3,465	0		22,856
Repurchase of common stock		(4,042)	(1,987)		(342)
Issuance of common stock		376	224		68
Other, net		(175)	(107)		(312)
NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES		(8,533)	(7,187)		23,515
Effect of foreign currency rate changes on cash, cash equivalents and restricted cash		41	(8)		(24)
Net increase in cash, cash equivalents and restricted cash		4,834	1,556		883
Cash, cash equivalents and restricted cash January 1,	[1]	5,411	3,855		2,972
Cash, cash equivalents and restricted cash, December 31,		10,245	5,411	[1]	3,855	[1]
Cash reclassified to assets of business held for sale		0	(743)		0
Cash, cash equivalents, and restricted cash December 31, per Consolidated Balance Sheets	[2]	10,245	4,668		3,855
Supplemental Disclosure of Cash Information:
Income taxes paid, net of refunds		1,837	1,776		1,019
Interest paid		$ 1,439	$ 1,645		$ 267

[1] Includes $743 million reported in Assets of business held for sale as of January 1, 2020. See table below for Cash, cash equivalents and restricted cash reconciliation.

[2] See table below for Cash, cash equivalents and restricted cash reconciliation as of December 31, 2020 and December 31, 2019.