Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Premiums	$ 74,186	$ 62,948	$ 54,941
Services	1,815	1,439	1,457
Investment income	1,154	501	514
Total revenues	77,155	64,888	56,912
Operating expenses:
Benefits	61,628	53,857	45,882
Operating costs	10,052	7,381	7,525
Depreciation and amortization	489	458	405
Total operating expenses	72,169	61,696	53,812
Income from operations	4,986	3,192	3,100
Loss on sale of business	0	0	786
Interest expense	283	242	218
Other expense (income), net	103	(506)	33
Income before income taxes and equity in net earnings	4,600	3,456	2,063
Provision for income taxes	1,307	763	391
Equity in net earnings	74	14	11
Net income	$ 3,367	$ 2,707	$ 1,683
Basic earnings per common share (in dollars per share)	$ 25.47	$ 20.20	$ 12.24
Diluted earnings per common share (in dollars per share)	$ 25.31	$ 20.10	$ 12.16
Services revenue, type	us-gaap:HealthCareService	us-gaap:HealthCareService	us-gaap:HealthCareService