XML 116 R87.htm IDEA: XBRL DOCUMENT v3.19.2
Derivatives - Classification of Gross Fair Values of Derivative Instruments, Excluding Cash Collateral (Detail) - Commodity derivatives - USD ($)
$ in Millions
Jun. 30, 2019
Dec. 31, 2018
Other current assets    
Derivatives, Fair Value [Line Items]    
Asset $ 237 $ 400
Liability 201 283
Other current liabilities(a)    
Derivatives, Fair Value [Line Items]    
Asset 2 1
Liability [1] 11 16
Deferred credits and other liabilities    
Derivatives, Fair Value [Line Items]    
Asset 0 0
Liability [1] $ 58 $ 54
[1]
Includes embedded derivatives.