Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income	$ 424	$ 960	$ 1,054	$ 1,312	$ 1,232	$ 747	$ 855	$ 1,009	$ 3,750	$ 3,843	$ 2,470
Other comprehensive income (loss), net of tax:
Change in net unrealized gains/losses on investments									(418)	173	118
Change in non-credit component of other-than-ternporary impairment losses on investments									(2)	4	5
Change in net unrealized gains/losses on cash flow hedges									37	(65)	(87)
Change in net periodic pension and postretirement costs									(90)	51	(13)
Foreign currency translation adjustments									(1)	3	2
Other comprehensive (loss) income									(474)	166	25
Total comprehensive income									3,276	4,009	2,495
Anthem, Inc. [Member]
Net income									3,750	3,843	2,470
Other comprehensive income (loss), net of tax:
Change in net unrealized gains/losses on investments									(418)	173	118
Change in non-credit component of other-than-ternporary impairment losses on investments									(2)	4	5
Change in net unrealized gains/losses on cash flow hedges									37	(65)	(87)
Change in net periodic pension and postretirement costs									(90)	51	(13)
Foreign currency translation adjustments									(1)	3	2
Other comprehensive (loss) income									(474)	166	25
Total comprehensive income									$ 3,276	$ 4,009	$ 2,495