XML 134 R73.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Medical Claims and Benefits Payable - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Insurance [Abstract]      
Medical claims and benefits payable $ 132 $ 107 $ 122
Favorable (unfavorable) adjustment $ (271) (341) $ 36
CMS Subsidies      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Disposal group, operating expense   $ 81