Parent Company Only Financial Statements - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$ 136,327	$ 97,723	$ 49,954	$ 67,597
Interest receivable	7,241	6,763
Other assets	51,354	27,577
Goodwill	46,867	46,904	46,904
Total assets	3,276,881	2,899,420	2,428,189
Liabilities:
Long-term debt	44,892	56,616
Accrued expenses and other liabilities	58,368	44,523
Total liabilities	2,946,383	2,662,746
Shareholders' equity :
Common stock	24,108	17,180
Additional paid-in capital	213,480	94,544
Retained earnings	93,784	122,493
Accumulated other comprehensive (loss) income	(874)	2,457
Total shareholders' equity	330,498	236,674	215,228	189,687
Total liabilities and shareholders' equity	3,276,881	2,899,420
Parent Company
ASSETS
Cash and cash equivalents	30,993	1,253	$ 551	$ 870
Investments	2,074	2,381
Investments in Bank subsidiary	325,574	265,632
Note receivable - Bank subsidiary		6,000
Interest receivable		31
Other assets	2,972	2,545
Goodwill	29	29
Total assets	361,642	277,871
Liabilities:
Long-term debt	30,930	35,005
Subordinated debt		6,000
Accrued expenses and other liabilities	214	192
Total liabilities	31,144	41,197
Shareholders' equity :
Common stock	24,108	17,180
Additional paid-in capital	213,480	94,544
Retained earnings	93,784	122,493
Accumulated other comprehensive (loss) income	(874)	2,457
Total shareholders' equity	330,498	236,674
Total liabilities and shareholders' equity	$ 361,642	$ 277,871