XML 87 R76.htm IDEA: XBRL DOCUMENT v3.10.0.1
Financial Instruments - Reconciliation of recurring Level 3 fair value measurements (Details)
$ in Millions
6 Months Ended
Jun. 30, 2018
USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Beginning balance $ 304
Purchases 36
Proceeds at maturity (30)
Ending balance $ 310