Other Assets and Liabilities from Related Parties (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Other current assets	$ 48	$ 110
Current Assets, Related Parties	594	656
Operating Lease, Right-of-Use Asset	341	365
Other Assets, Related Parties, Noncurrent	676	303
Operating Lease, Liability, Current	69	66
Current Liabilities, Related Parties	372	1,008
Operating Lease, Liability, Noncurrent	274	302
Liabilities, Related Parties, Noncurrent	287	290
MPC
Related Party Transaction [Line Items]
Receivables - related parties	547	621
Prepaid Insurance	11	9
Other current assets	1	0
Sales-type Lease, Interest Income	28	4
Sales-type Lease, Unguaranteed Residual Asset	20	7
Due from Related Parties, Noncurrent	30	21
Operating Lease, Right-of-Use Asset	231	232
Net Investment in Lease, Noncurrent	395	43
Due to Related Parties, Current	260	911
Operating Lease, Liability, Current	1	1
Operating Lease, Liability, Noncurrent	230	230
Other Affiliates [Member]
Related Party Transaction [Line Items]
Receivables - related parties	7	22
Due to Related Parties, Current	36	37
Minimum Committed Volume Contracts [Member] | MPC
Related Party Transaction [Line Items]
Deferred Revenue Related Parties	56	42
Reimbursable Projects [Member] | MPC
Related Party Transaction [Line Items]
Deferred Revenue Related Parties	18	16
Deferred Revenue, Noncurrent, Related Parties	51	53
Other Noncurrent Liabilities [Member] | Other Affiliates [Member]
Related Party Transaction [Line Items]
Deferred Revenue Related Parties	1	1
Other Noncurrent Liabilities [Member] | Other Affiliates [Member]
Related Party Transaction [Line Items]
Deferred Revenue, Noncurrent, Related Parties	$ 6	$ 7