Income Taxes - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) event	Dec. 31, 2016 USD ($)	Dec. 31, 2015	Jan. 08, 2016 USD ($)
Operating Loss Carryforwards [Line Items]
Re-measurement of net deferred tax liability, resulting in additional tax benefit	$ 1,900
U.S. federal statutory income tax rate	35.00%	35.00%	35.00%
Effective income tax rate	(29.17%)	50.75%	28.04%
Number of factors impacting net expense impact (in events) | event	3
Net income tax expense impact	$ 8,800
Impact to effective rate	65.20%
Permanent non-deductible acquisition transaction costs		$ 3,800
Effective income tax rate, uncertain tax position			4.80%
Valuation allowance	$ 1,605	1,624		$ 1,600
Domestic tax authority
Operating Loss Carryforwards [Line Items]
Federal net operating loss carryforward	53,900	70,500		82,900
State jurisdiction
Operating Loss Carryforwards [Line Items]
Federal net operating loss carryforward	$ 37,100	$ 46,500		$ 47,600