XML 99 R80.htm IDEA: XBRL DOCUMENT v3.10.0.1
Related Party Agreements and Transactions (Receivables from Related Parties) (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Related Party Transaction [Line Items]    
Receivables - related parties $ 289 $ 160
MPC    
Related Party Transaction [Line Items]    
Receivables - related parties 281 153
Other    
Related Party Transaction [Line Items]    
Receivables - related parties $ 8 $ 7