Income Taxes (Schedule of Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Federal, Current provision			$ (111)
Federal, Deferred provision	$ (1,512)	$ (131,344)	10,145
Federal, Total	(1,512)	(131,344)	10,034
Foreign, Current provision	84	134	206
Foreign, Total	84	134	206
State, Current provision	19		(519)
State, Deferred provision	715	(1,325)	(564)
State, Total	734	(1,325)	(1,083)
Provision for (benefit from) income taxes	$ (694)	$ (132,535)	$ 9,157