CONDENSED CONSOLIDATED STATEMENTS OF PREFERRED UNITS AND PARTNERS EARNINGS (DEFICIT) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Beginning Balance	$ (102,490)
Common stock awards under incentive plans	375
Net income (loss)	9,003	$ (22,534)
Ending Balance	(93,112)
Beginning Balance		(6,578)
Common unit awards under incentive plans		277
Ending Balance		$ (28,835)
Outstanding Common Units
Beginning Balance (in units)		37,958,645
Common unit awards under incentive plans (in units)		301,826
Ending Balance (in units)		38,260,471
Common Limited Partners
Net income (loss)		$ (22,300)
Beginning Balance		(2,570)
Common unit awards under incentive plans		277
Ending Balance		(24,593)
General Partner
Net income (loss)		(234)
Beginning Balance		(4,008)
Ending Balance		$ (4,242)
Common Stock
Beginning Balance	$ 944
Beginning Balance (in shares)	94,447,356
Common stock awards under incentive plans (in shares)	29,746
Ending Balance	$ 944
Ending Balance (in shares)	94,477,102
Paid-in Capital in Excess of Par Value
Beginning Balance	$ (103,434)
Common stock awards under incentive plans	375
Ending Balance	(103,059)
Retained Earnings
Net income (loss)	9,003
Ending Balance	$ 9,003