Interest Expense Components of Interest Expense (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest Expense [Abstract]
Interest Expense, Borrowings		$ 7,375	$ 8,945	$ 22,944	$ 27,960
Amortization of Debt Discount (Premium)	[1]	205	188	602	551
Amortization of Debt Issuance Costs		594	608	2,734	1,993
Interest Paid, Capitalized, Investing Activities		(677)	(1,005)	(2,067)	(3,234)
Interest Expense		7,497	8,736	24,213	27,270
Accelerated Deferred Debt Issuance Cost				900
Share-based compensation		$ 800	$ 1,000	$ 2,582	$ 3,101

[1] Attributable to the Second Lien Facility (see Note 7).