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Unit-Based Compensation (Details) - $ / shares	1 Months Ended			12 Months Ended
Unit-Based Compensation (Details) - $ / shares	Apr. 30, 2019	Mar. 31, 2019	Apr. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
LTIP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units available for issuance				840,811
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Units, Outstanding				513,694	283,138
Number of Restricted Units, Granted				1,129,173	622,534
Number of Restricted Units, Vested				(382,690)	(301,005)
Number of Restricted Units, Returned/Cancelled				(104,710)	(90,973)
Number of Restricted Units, Outstanding				1,155,467	513,694
Weighted Averaged Grant Date Fair Value Per Unit, Outstanding				$ 12.31	$ 14.64
Weighted Averaged Grant Date Fair Value Per Unit, Granted				2.35	11.94
Weighted Averaged Grant Date Fair Value Per Unit, Vested				8.50	13.60
Weighted Averaged Grant Date Fair Value Per Unit, Returned/Cancelled				12.04	12.77
Weighted Averaged Grant Date Fair Value Per Unit, Outstanding				$ 3.86	$ 12.31
Restricted Stock Units (RSUs) \| Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Units, Granted	137,613		63,630
Restricted Stock Units (RSUs) \| Executives
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Units, Granted		991,560	244,813
Vesting period		3 years	3 years
Restricted Stock Units (RSUs) \| Non executive employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Units, Granted			314,091