Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, at carrying value	$ 65,724	$ 71,491	$ 102,278		$ 80,783
Debt	525,057	525,355
Notes payable – related party	370,000	370,000
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, at fair value	65,724	71,491
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, at fair value	537,205	536,670
Notes payable – related party, at fair value	$ 370,000	$ 370,000
Senior Notes Due in 2026 [Member] | Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument stated rate (percent)		4.375%

[1] Financial information has been retrospectively adjusted for the acquisitions of the McKee Terminal Services Business and the Meraux and Three Rivers Terminal Services Business from Valero Energy Corporation. See Notes 1 and 2.