XML 85 R66.htm IDEA: XBRL DOCUMENT v3.7.0.1
Variable Interest Entities (VIEs) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Variable Interest Entity [Line Items]          
Administrative fee revenue $ 13 $ 13 $ 26 $ 27  
Variable Interest Entity, Primary Beneficiary          
Variable Interest Entity [Line Items]          
Amount paid for health care services 29 $ 31 60 $ 61  
Total carrying amount of assets 17   17   $ 18
Total amount of liabilities $ 18   $ 18   $ 18