Income Taxes - Summary of Components of Income Tax Expense (Benefit) (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
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, 2016
Dec. 31, 2015
Dec. 31, 2014
Current:                      
Federal                 $ 12,194 $ 9,060 $ 7,068
State                 1,850 1,452 1,087
Current                 14,044 10,512 8,155
Deferred:                      
Federal                 (670) (217) 78
State                 (101) (33) 13
Deferred                 (771) (250) 91
Income tax expense $ 3,433 $ 3,548 $ 3,407 $ 2,885 $ 2,493 $ 2,844 $ 2,449 $ 2,476 $ 13,273 $ 10,262 $ 8,246