Income Taxes - Schedule of Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net operating losses and tax credits	$ 26,296	$ 45,947
Property and equipment	8,289	12,995
AMT minimum tax receivable	2,489	2,199
Accruals and accrued loss contingencies	4,833	6,723
Intangible assets	6,033	5,886
Gross deferred income tax assets	47,940	73,750
Prepaid and other expenses	(261)	(682)
Gross deferred income tax liabilities	(261)	(682)
Net deferred income tax assets	$ 47,679	$ 73,068