Equity - Private Perpetual Preferred Units (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Preferred Units [Line Items]
Dividends per share (in USD per share)	$ 0.035	$ 0.105	$ 0.035	$ 0.210
Private Perpetual Preferred Units, Series 2019
Preferred Units [Line Items]
Private perpetual preferred units, issued (in shares)	4,664,038		4,664,038		4,664,000
Private perpetual preferred units, per unit liquidation preference (in USD per share)	$ 13.52		$ 13.52		$ 13.52
Cumulative preferential annual cash distributions (in USD per share)	$ 0.70		$ 0.70
Private Perpetual Preferred Units, Series 2014
Preferred Units [Line Items]
Private perpetual preferred units, issued (in shares)	1,560,000		1,560,000		1,560,000
Private perpetual preferred units issued during period (in shares)			1,560,360
Private perpetual preferred units, per unit liquidation preference (in USD per share)	$ 16.62		$ 16.62		$ 16.62
Dividends per share (in USD per share)			$ 0.60