Fair Value Measurements (Reconciliation of Level 3 Fair Valued Instruments) (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest rate reset
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net	$ (7,500)	$ (4,500)
Change of control redemption
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net	(1,600)	(600)
Qualifying change of control
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net	(1,200)
Financing Derivative Liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	21,587	26,100
Settlement		587
Settlement		0
Total loss (gain) included in other income (expense), net	(10,287)	(5,100)
Ending Balance	11,300	21,587
Warrants Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	7,725	0
Settlement		10,798
Settlement		(5,484)
Total loss (gain) included in other income (expense), net	(4,894)	2,411
Ending Balance	2,831	7,725
Interest Make-whole Derivative Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0	0
Settlement		0
Settlement		0
Total loss (gain) included in other income (expense), net	871	0
Ending Balance	871	0
Series A Warrants | Warrants Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net	(4,700)	3,600
Series B-1 Warrants | Warrants Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net		(300)
Series B-2 Warrant | Warrants Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net	$ (200)	(200)
Series C Warrants | Warrants Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total loss (gain) included in other income (expense), net		$ (700)