Partners' Capital - Schedule of Outstanding Capital Units (Detail) - shares		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Limited Partner Common Units [Member]
Limited Partners Capital Account [Line Items]
Units outstanding, beginning balance		13,174,410	6,867,950
Vesting of equity-based compensation awards		221,530	39,996
Conversion of subordinated units to common units		6,081,081
Units outstanding, ending balance		19,477,021	13,174,410
Limited Partner Common Units [Member] | Private Placement [Member]
Limited Partners Capital Account [Line Items]
Issuance of common units	[1]		4,520,795
Limited Partner Common Units [Member] | United Energy Trading [Member]
Limited Partners Capital Account [Line Items]
Issuance of common units	[2]		1,745,669
Limited Partner Subordinated Units [Member]
Limited Partners Capital Account [Line Items]
Units outstanding, beginning balance		6,081,081	6,081,081
Conversion of subordinated units to common units		(6,081,081)
Units outstanding, ending balance			6,081,081

[1] Refer to “Note 3—Acquisitions – JBBR Acquisition” for further discussion of these units

[2] Refer to “Note 3 – Acquisitions – Pawnee Terminal Acquisition” for further discussion of these units