Quarterly report pursuant to Section 13 or 15(d)

Affordable Care Act (Details)

v3.10.0.1
Affordable Care Act (Details) - USD ($)
$ in Millions
3 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Sep. 30, 2018
Dec. 31, 2017
Affordable Care Act [Abstract]        
Risk adjustment pre-tax benefit $ 79 $ 48    
Risk adjustment     $ (784) $ (677)
Reinsurance     1 15
Risk corridor     4 6
Minimum MLR     (154) (22)
Cost sharing reductions     $ (61) $ (96)