Derivative Instruments - Realized and Unrealized Gain (Loss) on Derivatives Not Designated as Hedging Instruments (Details) - Derivatives not designated as hedging instruments: - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Unrealized Gain (Loss)	$ 4,021	$ (41,217)	$ 29,278
Realized Gain (Loss)	3,256	129,509	(622)
Total Gain (Loss)	7,277	88,292	28,656
Contingent redemption features - Series A Preferred
Derivative [Line Items]
Unrealized Gain (Loss)	0	(42,140)	33,294
Realized Gain (Loss)	0	140,320	0
Total Gain (Loss)	0	98,180	33,294
Cross currency and interest rate swaps
Derivative [Line Items]
Unrealized Gain (Loss)	4,021	750	(4,191)
Realized Gain (Loss)	3,256	(10,811)	(622)
Total Gain (Loss)	7,277	(10,061)	(4,813)
Interest rate swaps
Derivative [Line Items]
Unrealized Gain (Loss)	0	173	175
Total Gain (Loss)	$ 0	$ 173	$ 175