Income Taxes - Deferred Tax Asset Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance, Deferred Tax Asset [Roll Forward]
Balance, Beginning of Period	$ 75,436	$ 58,748	$ 59,806
Charged to Costs & Expenses	29,576	13,243	0
Charged to Other Accounts	(714)	3,445	0
Deductions	0	0	(1,058)
Balance, end of Period	$ 104,298	$ 75,436	$ 58,748