CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Net income	$ 43,220	$ 31,082	$ 41,311
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation and amortization of premises and equipment	3,151	2,704	2,309
Provision for loan losses	6,000	38,700	12,605
Increase to valuation allowance, loans held-for-sale	15,592
Amortization of intangibles	724	820	917
Net accretion of loans	(2,073)	(4,280)	(5,052)
Accretion on bank premises	(74)	(132)	(108)
Accretion on deposits	(31)	(172)	(470)
Accretion on borrowings	(203)	(307)	(441)
Net deferred income tax expense (benefit)	3,699	1,969	(3,493)
Stock-based compensation	1,778	2,113	747
Gains on sales of investment securities, net	(1,596)	(4,234)	(3,931)
Gains on sale of loans held-for-sale, net	(708)	(232)	(327)
Loans originated for resale	(9,083)	(10,004)	(20,834)
Proceeds from sale of loans held-for-sale	63,731	10,048	21,161
Net gains on disposition of premises and equipment	(8)	(57)
Net loss (gain) on sale of other real estate owned	82	(182)	164
Increase in cash surrender value of bank owned life insurance	(2,952)	(2,559)	(1,782)
Loss on extinguishment of debt			2,397
Amortization of premiums and accretion of discounts on investments securities, net	2,631	1,692	1,793
Amortization of subordinated debt issuance costs	165	191	89
Increase in accrued interest receivable	(2,505)	(420)	(845)
Decrease (Increase) in other assets	5,706	(15,006)	1,101
Increase (Decrease) in other liabilities	3,887	(2,022)	(1,080)
Net cash provided by operating activities	131,133	49,712	46,231
Investment securities available-for-sale:
Purchases	(224,621)	(165,527)	(37,403)
Sales	29,543	85,253	65,231
Maturities, calls and principal repayments	109,104	137,587	62,007
Investment securities held-to-maturity:
Purchases		(1,000)	(17,531)
Maturities and principal repayments		14,757	17,520
Net redemptions (purchases) of restricted investment in bank stocks	(9,187)	8,302	(9,077)
Loans held-for-sale payments	3,122
Net increase in loans	(714,159)	(490,777)	(557,881)
Purchases of premises and equipment	(2,661)	(2,702)	(3,881)
Purchases of bank owned life insurance	(10,000)	(16,999)	(24,501)
Proceeds from sale of premises and equipment	8	445
Proceeds from sale of other real estate owned	1,124	2,992	769
Net cash used in investing activities	(817,727)	(427,669)	(504,747)
Cash flows from financing activities
Net increase in deposits	450,888	553,477	315,829
Increase in subordinated debt			50,000
Advances of FHLB borrowings	1,280,000	375,000	848,875
Repayments of FHLB borrowings	(1,071,000)	(570,000)	(656,400)
Repayment of repurchase agreement	(15,000)		(18,397)
Cash dividends paid on common stock	(9,612)	(9,067)	(8,996)
Cash dividends paid on preferred stock		(22)	(112)
Redemption of preferred stock		(11,250)
Issuance cost of common stock	(180)
Secondary offering of common stock		38,439
Tax benefit of options exercised	264	117	341
Proceeds from exercise of stock options	417	767	1,424
Net cash provided by financing activities	635,777	377,461	532,564
Net change in cash and cash equivalents	(50,817)	(496)	74,048
Cash and cash equivalents at beginning of period	200,399	200,895	126,847
Cash and cash equivalents at end of period	149,582	200,399	200,895
Interest paid	36,721	30,862	23,357
Income taxes paid	16,205	22,945	17,880
Investing:
Transfer of loans to other real estate owned	1,118	887	2,374
Transfer of loan held-for-sale to loans held-for-investment	54,422
Transfer of loans held-for-investment to loans held-for-sale	73,916	77,817
Transfer from investment securities held-to-maturity to investment securities available-for-sale		$ 209,855