Interest Expense Components of Interest Expense (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Banking and Thrift [Abstract]
Interest Expense, Borrowings		$ 9,304	$ 7,730	$ 19,015	$ 13,778
Amortization of Debt Discount (Premium)	[1]	183	168	363	333
Amortization of Debt Issuance Costs		644	680	1,385	1,311
Interest Paid, Capitalized, Investing Activities		(1,075)	(2,428)	(2,229)	(4,671)
Interest Expense		$ 9,056	$ 6,150	$ 18,534	$ 10,751

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