Income Taxes - Reconciliation of income tax at the federal statutory rate to the actual effective income tax rate (benefit) (Details)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Income Tax Disclosure [Abstract]      
Federal statutory rate (35.00%) (35.00%) (34.00%)
Foreign rate differential 0.20% 0.70% (0.00%)
State income taxes, net of federal benefit (0.00%) (2.50%) (0.80%)
Nondeductible loan costs 1.80% 1.50% (0.00%)
Nondeductible transaction costs (0.00%) 1.60% (0.00%)
Other differences 3.20% 0.20% 0.60%
Expiration of tax credits 1.90% (0.00%) (0.00%)
Uncertain tax positions 0.60% 0.30% (0.00%)
Valuation allowance 23.70% (15.20%) 42.60%
Effective income tax rate (3.60%) (48.40%) 8.40%