Income Taxes - Tax Effects Of Temporary Differences Which Give Rise To Deferred Tax Assets And Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Medical claims liability	$ 120	$ 107
Nondeductible liabilities	215	145
Net operating loss and tax credit carryforwards	357	124
Compensation accruals	205	205
Premium and trade receivables	143	161
Operating lease liability	445	386
Other	112	69
Deferred tax assets	1,597	1,197
Valuation allowance	(212)	(73)
Net deferred tax assets	1,385	1,124
Deferred tax liabilities:
Goodwill and intangible assets	1,794	1,805
Prepaid assets	46	33
Fixed assets	409	351
Right of use asset	444	337
Unrealized gain/loss	29	105
Other	70	27
Deferred tax liabilities	2,792	2,658
Deferred tax liabilities, net	$ (1,407)	$ (1,534)