CONDENSED CONSOLIDATED STATEMENTS OF PREFERRED UNITS AND PARTNERS EARNINGS (DEFICIT) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Beginning Balance	$ (79,709)	$ (93,112)	$ (102,490)				$ (102,490)
Beginning Balance				$ (3,444)	$ (28,835)	$ (6,578)		$ (6,578)
Issuance of Series A Preferred Stock/Units		8,800			57,500
Issuance of Common Stock		8,200
Common stock awards under incentive plans	352	317	375
Common unit awards under incentive plans				248	2,289	277
Units repurchased and retired related to unit-based compensation				(677)
Net income (loss)	(7,857)	(3,914)	9,003	(42,652)	(34,398)	(22,534)	(2,768)	(99,584)
Ending Balance	(87,214)	$ (79,709)	(93,112)				(87,214)
Ending Balance				(46,525)	(3,444)	$ (28,835)		(46,525)
Redeemable Convertible Preferred Units Series A
Beginning Balance				$ 57,500
Beginning Balance (in units)				52,083,333
Issuance of Series A Preferred Stock/Units					$ 57,500
Issuance of Series A Preferred Stock\units (in shares\units)					52,083,333
Ending Balance				$ 57,500	$ 57,500			$ 57,500
Ending Balance (in units)				52,083,333	52,083,333			52,083,333
Outstanding Common Units
Beginning Balance (in units)				39,533,847	38,260,471	37,958,645		37,958,645
Common unit awards under incentive plans (in units)				31,983	1,273,376	301,826
Units repurchased related to unit-based compensation (in units)				(376)
Ending Balance (in units)				39,565,454	39,533,847	38,260,471		39,565,454
Common Limited Partners
Beginning Balance				$ (56,347)	$ (24,593)	$ (2,570)		$ (2,570)
Common unit awards under incentive plans				250	2,287	277
Units repurchased and retired related to unit-based compensation				(677)
Net income (loss)				(42,225)	(34,041)	(22,300)
Ending Balance				(98,999)	(56,347)	(24,593)		(98,999)
General Partner
Beginning Balance				(4,597)	(4,242)	(4,008)		(4,008)
Common unit awards under incentive plans				(2)	2
Net income (loss)				(427)	(357)	(234)
Ending Balance				$ (5,026)	$ (4,597)	$ (4,242)		$ (5,026)
Series A Preferred Stock
Issuance of Series A Preferred Stock\units (in shares\units)		176
Exchange of Series A Preferred Stock for Common Stock (in shares)		(176)
Common Stock
Beginning Balance	$ 1,177	$ 944	$ 944				$ 944
Beginning Balance (in shares)	117,794,520	94,477,102	94,447,356				94,447,356
Exchange of Series A Preferred Stock for Common Stock		$ 121
Exchange of Series A Preferred Stock for Common Stock (in shares)		12,054,795
Issuance of Common Stock		$ 112
Issuance of Common Stock (in shares)		11,232,877
Common stock awards under incentive plans	$ 1
Common stock awards under incentive plans (in shares)	29,746	29,746	29,746
Ending Balance	$ 1,178	$ 1,177	$ 944				$ 1,178
Ending Balance (in shares)	117,824,266	117,794,520	94,477,102				117,824,266
Paid-in Capital in Excess of Par Value
Beginning Balance	$ (85,975)	$ (103,059)	$ (103,434)				$ (103,434)
Issuance of Series A Preferred Stock/Units		8,800
Exchange of Series A Preferred Stock for Common Stock		(121)
Issuance of Common Stock		8,088
Common stock awards under incentive plans	351	317	375
Ending Balance	(85,624)	(85,975)	(103,059)				(85,624)
Retained Earnings (Deficit)
Beginning Balance	5,089	9,003
Net income (loss)	(7,857)	(3,914)	9,003
Ending Balance	$ (2,768)	$ 5,089	$ 9,003				$ (2,768)