CONSOLIDATED STATEMENTS OF MEMBERS’ EQUITY - USD ($) $ in Thousands	Total	Units	Members’ Equity	Accumulated Other Comprehensive (Loss) Income
Balance at Dec. 31, 2014	$ 310,836		$ 316,611	$ (5,775)
Balance in units at Dec. 31, 2014		42,913,277
Net income	72,208		72,208	0
Other comprehensive income (loss)	(2,889)		0	(2,889)
Distributions to unitholders	(93,567)		(93,567)	0
Unit-based compensation	468		468	0
Unit-based compensation in units		17,272
Other	14		14	0
Balance in units at Dec. 31, 2015		42,930,549
Balance at Dec. 31, 2015	287,070		295,734	(8,664)
Net income	55,068		55,068	0
Other comprehensive income (loss)	(5,210)		0	(5,210)
Distributions to unitholders	(93,590)		(93,590)	0
Unit-based compensation	450		450	0
Unit-based compensation in units		21,200
Balance in units at Dec. 31, 2016		42,951,749
Balance at Dec. 31, 2016	243,788		257,662	(13,874)
Net income	86,775		86,775	0
Other comprehensive income (loss)	3,052		0	3,052
Distributions to unitholders	(93,634)		(93,634)	0
Unit-based compensation	555		555	0
Unit-based compensation in units		25,383
Balance in units at Dec. 31, 2017		42,977,132
Balance at Dec. 31, 2017	$ 240,536		$ 251,358	$ (10,822)