Income Taxes - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Operating Loss Carryforwards [Line Items]
Consolidated effective tax rate									11.50%	109.70%	(77.50%)
Tax Cuts And Jobs Act Of 2017, change in tax rate, provisional income tax benefit										$ 5,900
Deferred tax liabilities, provisional income tax benefit (in usd per share)										$ 0.21
Valuation allowance	$ 11,000								$ 11,000
Valuation allowance per share (in dollars per share)	$ 0.39								$ 0.39
Goodwill impairment charges	$ 69,500								$ 69,483	$ 0	$ 0
(Loss) income before income taxes	(106,727)	$ (9,427)	$ 3,909	$ 5,590	$ 9,306	$ (6,703)	$ (3,917)	$ (2,827)	(106,655)	(4,141)	(2,039)
Goodwill impairment, permanent difference									1,200
Unrecognized tax benefit	1,614				1,614				1,614	1,614	$ 0
Retained earnings	$ (31,861)				62,847				$ (31,861)	62,847		$ 62,561
Accounting Standards Update 2016-09
Operating Loss Carryforwards [Line Items]
Retained earnings					$ 700					$ 700