Income Taxes (Deferred Tax Assets and Liabilities by Balance Sheet Classification (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets and Liabilities by Balance Sheet Classification [Abstract]
Deferred tax assets	$ 136,998	$ 152,362
Deferred tax liabilities	(15,075)	(237)
Total net deferred tax assets	$ 121,923	$ 152,125