Supplemental Cash Flow Information - Reconciliation of Additions to Property, Plant and Equipment to Total Capital Expenditures (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Supplemental Cash Flow Elements [Abstract]    
Additions to property, plant and equipment per consolidated statements of cash flows $ 755 $ 610
Asset retirement expenditures 1 1
Decrease in capital accruals (49) (72)
Total capital expenditures before acquisitions 707 539
Acquisitions 0 220 [1]
Capital expenditures [2] $ 707 $ 759
[1] The three months ended March 31, 2017 reflects the acquisition of the Ozark pipeline.
[2] Capital expenditures include changes in capital accruals. See Note 18 for a reconciliation of total capital expenditures to additions to property, plant and equipment as reported in the consolidated statements of cash flows.Revenues by product line were as follows: Three Months Ended March 31,(In millions)2018 2017Refined products$16,158 $13,876Merchandise1,130 1,192Crude oil and refinery feedstocks883 687Service, transportation and other523 379Sales and other operating revenues $18,694 $16,134