Unaudited Quarterly Financial Data - Summary of Unaudited Quarterly Financial Data (Details) - USD ($)
$ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]                      
Net interest income $ 18,333 $ 17,637 $ 17,211 $ 16,700 $ 16,449 $ 15,789 $ 14,903 $ 14,499 $ 69,881 $ 61,640 $ 54,943
Provision for loan losses 150 325 225 200 200 200 450 150 900 1,000 1,700
Non-interest income 4,332 4,386 4,398 3,763 3,752 3,965 4,143 4,144 16,879 16,004 15,241
Non-interest expense 12,540 11,902 12,400 12,135 12,622 11,444 11,483 11,219 48,977 46,768 45,333
Income before income tax expense 9,975 9,796 8,984 8,128 7,379 8,110 7,113 7,274 36,883 29,876 23,151
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
Net income $ 6,542 $ 6,248 $ 5,577 $ 5,243 $ 4,886 $ 5,266 $ 4,664 $ 4,798 $ 23,610 $ 19,614 $ 14,905
Earnings per common share:                      
Basic $ 0.37 $ 0.35 $ 0.31 $ 0.30 $ 0.28 $ 0.30 $ 0.31 $ 0.32 $ 1.33 $ 1.21 $ 1.02
Diluted $ 0.36 $ 0.34 $ 0.31 $ 0.29 $ 0.27 $ 0.29 $ 0.30 $ 0.31 $ 1.30 $ 1.17 $ 0.98