Consolidated Statements of Operations - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Affiliate		$ 100,808	$ 95,470	$ 42,549	[1]
Non-affiliate		6,185	8,302	8,388	[1]
Total revenues		106,993	103,772	50,937	[1]
Operating expenses
Operations and maintenance (excluding depreciation and amortization reflected below)		33,501	34,211	29,601	[1]
General and administrative		4,223	4,423	3,114	[1]
Depreciation and amortization		5,111	5,647	5,828	[1],[2]
Total operating expenses		42,835	44,281	38,543	[1]
Operating income		64,158	59,491	12,394	[1]
Other income (expense)
Interest income		81	83	86	[1]
Interest expense		(5,402)	(2,545)	(381)	[1]
Other, net		150
Total other expense		(5,171)	(2,462)	(295)	[1]
Income before income taxes		58,987	57,029	12,099	[1]
Income tax (expense) benefit		(109)	(224)	4,009	[1]
Equity investment loss		(11)
Net income		58,867	56,805	16,108	[1],[2]
Net loss attributable to MLP predecessor	[1]			(6,628)
Net loss attributable to sponsor	[1]			(273)
Net income attributable to the partnership		58,867	56,805	23,009	[1]
General Partner [Member]
Other income (expense)
Net income attributable to the partnership		1,177	1,136	460
Net income attributable to partners' ownership interests: General partner		1,177	1,136	460	[1]
Limited Partners [Member] | Common Units [Member]
Other income (expense)
Net income attributable to the partnership		28,869	27,848	11,278
Net income attributable to partners' ownership interests: Limited partners		$ 28,869	$ 27,848	$ 11,278	[1]
Earnings per limited partner unit (basic and diluted):
Earnings per limited partner unit (basic and diluted)		$ 1.81	$ 1.75	$ 0.71	[1]
Weighted average limited partner units outstanding (basic and diluted):
Weighted average limited partner units outstanding (basic and diluted)		15,916,000	15,904,000	15,897,000	[1]
Limited Partners [Member] | Subordinated Units [Member]
Other income (expense)
Net income attributable to the partnership		$ 28,821	$ 27,821	$ 11,271
Net income attributable to partners' ownership interests: Limited partners		$ 28,821	$ 27,821	$ 11,271	[1]
Earnings per limited partner unit (basic and diluted):
Earnings per limited partner unit (basic and diluted)		$ 1.81	$ 1.75	$ 0.71	[1]
Weighted average limited partner units outstanding (basic and diluted):
Weighted average limited partner units outstanding (basic and diluted)		15,890,000	15,890,000	15,890,000	[1]

[1] Recast to include historical results of operations related to net assets acquired in a transfer between entities under common control. See Notes 1 and 4 in the accompanying notes to consolidated financial statements for further discussion.

[2] Recast to include historical cash flow activity related to net assets acquired in a transfer between entities under common control. See Notes 1 and 4 in the accompanying notes to consolidated financial statements for further discussion.