Amount, after reinsurance, of paid claims and allocated claim adjustment expense used in claims development for short-duration insurance contracts. Excludes unallocated claim adjustment expense.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 4B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=116884468&loc=SL65671311-158438

Name:	us-gaap_ShortdurationInsuranceContractsCumulativePaidClaimsAndAllocatedClaimAdjustmentExpenseNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Medical Claims and Benefits Payable - Cumulative Paid Claims and Allocated Claims Adjustment Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Product Information [Line Items]
Claims paid	$ 43,149
Benefit Year 2018
Product Information [Line Items]
Claims paid	15,222	$ 15,220	$ 13,752
Benefit Year 2019
Product Information [Line Items]
Claims paid	14,056	$ 12,554
Benefit Year 2020
Product Information [Line Items]
Claims paid	$ 13,871