Schedule I - Condensed Financial Information, Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Net investment (income)									$ 1,390	$ 1,480	$ 1,226
Total revenues	$ 38,245	$ 38,556	$ 38,819	$ 37,946	$ 14,300	$ 11,457	$ 11,480	$ 11,413	153,566	48,650	41,806
Operating expenses:
Selling, Genernal and Administrative Expense									14,053	11,934	10,030
Total benefits and expenses									145,489	44,490	37,864
Income from operations									8,077	4,160	3,942
Interest expense and other									(1,682)	(498)	(252)
Debt extinguishment costs									(2)	0	(321)
Net realized investment gains (losses)									177	(81)	237
Income (loss) before income taxes	1,261	1,763	1,758	1,788	228	1,033	1,102	1,218	6,570	3,581	3,606
Income tax expense (benefit)									1,450	935	1,374
Shareholders' net income	$ 977	$ 1,351	$ 1,408	$ 1,368	$ 144	$ 772	$ 806	$ 915	5,104	2,637	2,237
Shareholders' other comprehensive income (loss), net of tax:
Shareholders' comprehensive income (loss)									5,874	2,247	2,537
Cigna [Member]
Revenues
Net investment (income)									0	123
Intercompany interest income									6	0
Total revenues									6	123
Operating expenses:
Selling, Genernal and Administrative Expense									(85)	200
Total benefits and expenses									(85)	200
Income from operations									91	(77)
Interest expense and other									(1,032)	(244)
Intercompany interest income (expense)									(127)	(5)
Debt extinguishment costs									0	0
Net realized investment gains (losses)									0	(1)
Income (loss) before income taxes									(1,068)	(327)
Income tax expense (benefit)									(251)	(74)
(Loss) of parent company									(817)	(253)
Equity in income from subsidiaries									5,921	2,890
Shareholders' net income									5,104	2,637
Shareholders' other comprehensive income (loss), net of tax:
Net unrealized appreciation (depreciation) on securities and derivatives									957	(365)
Net translation (losses) gains on foreign currencies									(54)	(152)
Postretirement benefits liability adjustment									(133)	127
Shareholders' other comprehensive income (loss)									770	(390)
Shareholders' comprehensive income (loss)									$ 5,874	$ 2,247
Old Cigna [Member]
Revenues
Net investment (income)											0
Intercompany interest income											0
Total revenues											0
Operating expenses:
Selling, Genernal and Administrative Expense											195
Total benefits and expenses											195
Income from operations											(195)
Interest expense and other											(246)
Intercompany interest income (expense)											(18)
Debt extinguishment costs											(321)
Net realized investment gains (losses)											0
Income (loss) before income taxes											(780)
Income tax expense (benefit)											(194)
(Loss) of parent company											(586)
Equity in income from subsidiaries											2,823
Shareholders' net income											2,237
Shareholders' other comprehensive income (loss), net of tax:
Net unrealized appreciation (depreciation) on securities and derivatives											(37)
Net translation (losses) gains on foreign currencies											304
Postretirement benefits liability adjustment											33
Shareholders' other comprehensive income (loss)											300
Shareholders' comprehensive income (loss)											$ 2,537