Summary of Significant Accounting Policies (Other Income (Expense), Net) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Change in fair value of financing derivatives									$ 10,287	$ 5,100	$ (14,226)
Change in fair value of warrants liability									4,894	(2,411)	0
Change in fair value of interest make-whole derivative									(871)	0	0
Change in fair value of investment in equity securities									0	(2,324)	1,443
Transition services agreement income									0	534	9,029
Other									244	755	2,290
Total other income (expense), net	$ 1,692	$ 4,191	$ 1,477	$ 7,194	$ (4,967)	$ 6,733	$ (3,081)	$ 2,969	$ 14,554	$ 1,654	$ (1,464)