Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Premiums	$ 18,556	$ 15,776	$ 36,918	$ 31,427
Services	450	355	874	710
Investment income	77	114	226	215
Total revenues	19,083	16,245	38,018	32,352
Operating expenses:
Benefits	14,175	13,318	29,804	26,811
Operating costs	2,354	1,703	4,471	3,363
Depreciation and amortization	119	109	234	216
Total operating expenses	16,648	15,130	34,509	30,390
Income from operations	2,435	1,115	3,509	1,962
Interest expense	76	60	136	122
Other (income) expense, net	(227)	(174)	70	(135)
Income before income taxes and equity in net earnings	2,586	1,229	3,303	1,975
Provision for income taxes	783	301	1,035	484
Equity in net earnings	25	12	33	15
Net income	$ 1,828	$ 940	$ 2,301	$ 1,506
Basic earnings per common share (in dollars per share)	$ 13.83	$ 6.96	$ 17.41	$ 11.14
Diluted earnings per common share (in dollars per share)	$ 13.75	$ 6.94	$ 17.31	$ 11.10
Services revenue, type [Extensible List]	us-gaap:HealthCareService	us-gaap:HealthCareService	us-gaap:HealthCareService	us-gaap:HealthCareService