Equity Method Investments (Schedule Of Equity Method Investments) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016		May 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Mar. 04, 2014
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 3,827			$ 3,622
MPLX LP
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 2,467			2,458
Centennial
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		50.00%
Equity method investments		$ 35			37
Centrahoma Processing LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		40.00%
Equity method investments		$ 104			111
Crowley Coastal Partners
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		50.00%		50.00%
Equity method investments		$ 184			0
Crowley Ocean Partners
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		50.00%		50.00%		50.00%
Equity method investments		$ 0	[1]		72
Explorer
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		25.00%					25.00%
Equity method investments		$ 94			91
Illinois Extension Pipeline
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		35.00%
Equity method investments		$ 293			267
LOCAP
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		59.00%
Equity method investments		$ 22			22
LOOP
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		51.00%
Equity method investments		$ 277			243
MarkWest Utica EMG
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		56.00%
Equity method investments		$ 2,224			2,160
North Dakota Pipeline
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments from asset impairment		$ (267)
Equity method investments, ownership percentage		37.50%
Equity method investments		$ 30	[2]		287
Ohio Condensate
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments from asset impairment		$ (89)
Equity method investments, ownership percentage		60.00%
Equity method investments		$ 10	[2]		101
PFJ Southeast
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		29.00%
Equity method investments		$ 283	[3]		0
TAAE
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		45.00%
Equity method investments		$ 33			27
TACE
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		61.00%
Equity method investments		$ 33			49
TAEI
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		34.00%
Equity method investments		$ 15			18
TAME
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		67.00%
TAME | Direct Ownership Interest
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		50.00%
Equity method investments	[4]	$ 18			27
Other equity method investees
Schedule of Equity Method Investments [Line Items]
Equity method investments		43			24
Other equity method investees | MPLX LP
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 129			$ 86

[1] Crowley Ocean Partners merged into Crowley Coastal Partners in 2016.

[2] During 2016, we recorded an impairment charge of $267 million related to our investment in North Dakota Pipeline and an impairment charge of $89 million related to our investment in Ohio Condensate. See Note 17 for additional information.

[3] This joint venture with Pilot Flying J was formed in 2016. See Note 5.

[4] Excludes TAEI’s investment in TAME.