v3.8.0.1
Income Taxes - Schedule of Reconciliation of Statutory Income Taxes and Effective Income Taxes (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount [Abstract]                              
Income before taxes $ 13,040 $ 14,209 $ 14,287 $ 9,063 $ 10,599 $ 15,475 $ 5,731 $ 6,529 $ 8,345 $ 4,803 $ 5,117 $ 4,567 $ 50,599 $ 38,334 $ 22,832
Federal statutory income tax, amount                         17,710 13,417 7,991
State tax, net of Federal benefit, amount                         3,313 2,510 1,536
Windfall benefit - exercise of stock options, amount                         (3,762) (1,025)  
Change in federal rate, amount                         5,414    
Other items, net, amount                         342 129 (73)
Total $ 10,767 $ 4,629 $ 4,671 $ 2,950 $ 4,082 $ 5,800 $ 2,407 $ 2,742 $ 3,297 $ 2,041 $ 2,175 $ 1,941 $ 23,017 $ 15,031 $ 9,454
Effective Income Tax Rate Reconciliation, Percent [Abstract]                              
Federal statutory income tax rate                         35.00% 35.00% 35.00%
State tax, net of Federal benefit, rate                         6.55% 6.55% 6.73%
Windfall benefit - exercise of stock options, rate                         (7.43%) (2.67%)  
Change in federal rate                         10.70%    
Other items, net, rate                         0.68% 0.34% (0.32%)
Effective income tax rate                         45.49% 39.22% 41.41%