Income Taxes - Schedule of Components of Income Tax Expense (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Components      
United States $ 34,386 $ 37,276 $ 33,274
Foreign 2,194 (89) 157
Income from operations before income taxes 36,580 37,187 33,431
Current income tax provision      
United States-Federal 11,952 15,106 10,549
United States-State and local 206 311 401
Foreign 758 371 910
Total current income tax provision 12,916 15,788 11,860
Deferred income tax provision (benefit)      
United States-Federal (35,486) (1,733) (9,350)
United States-State and local (260) (278) (42)
Foreign (87) (245) (10)
Total deferred income tax provision (benefit) (35,833) (2,256) (9,402)
Total income tax (benefit) expense $ (22,917) $ 13,532 $ 2,458
Effective income tax rate (62.60%) 36.40% 7.40%