CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Operating activities:
Net income	$ 10,813	$ 11,225
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,905	1,683
Provision (credit) for loan and lease losses	1,236	597	$ 5,371
Share based compensation expense	477	422
Deferred income tax expense	626	669
Origination of loans held for sale	(26,862)	(44,128)
Proceeds from sales of loans held for sale	32,592	41,336
Gains on sales of loans held for sale	493	(595)
Loss on sales of other real estate owned	72	0
Investment securities gains	(1,769)	0
Increase (Decrease) in Operating Capital [Abstract]
Net (increase) decrease in accrued interest receivable	(239)	129
Net (increase) decrease in other assets	(565)	(1,763)
Net increase (decrease) in accrued expenses and other liabilities	(3,731)	(334)
Other - net	788	1,054
Net cash provided by operating activities	15,836	10,295
Investing activities:
Proceeds of other equity securities	3,807	4,138
Proceeds from sales of investment available-for-sale	40,863	0
Proceeds from maturities, calls and principal payments of investments held-to-maturity	5,004	2,195
Proceeds from maturities, calls and principal payments of investments available-for-sale	59,561	18,628
Net increase in loans and leases	(83,890)	(38,270)
Proceeds from the sales of other real estate owned	163	0
Expenditures for premises and equipment	(1,451)	(3,045)
Net cash used in investing activities	24,057	(16,354)
Financing activities:
Net increase (decrease) in deposits	148,578	43,383
Net increase (decrease) in retail repurchase agreements and federal funds purchased	11,898	27,208
Proceeds from advances from FHLB	760,000	569,000
Repayment of advances from FHLB	(855,000)	(634,000)
Proceeds from issuance of common stock	184	(146)
Tax benefits associated with shared based compensation	77	146
Repurchase of common stock	(13,273)	(9,038)
Dividends paid	(5,843)	(5,561)
Net cash provided by financing activities	46,621	(9,008)
Net increase (decrease) in cash and cash equivalents	86,514	(15,067)
Cash and cash equivalents at beginning of period	72,882	96,217	96,217
Cash and cash equivalents at end of period	159,396	81,150	$ 72,882
Supplemental Disclosures:
Interest payments	5,795	4,746
Income tax payments	6,396	4,360
Transfer of Investments Held-to-maturity to Available For Sale Securities	203,118	0
Transfer from loans to residential mortgage loans held for sale	$ 18,752	$ 0