CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Operating activities:
Net income	$ 14,741	$ 10,647	$ 29,853	$ 21,460
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization			3,967	3,897
Provision for loan losses	1,322	2,957	1,516	4,193	$ 5,546
Share based compensation expense			1,052	992
Tax benefits associated with share based compensation			692	267
Deferred income tax expense			(540)	60
Origination of loans held for sale			(70,736)	(72,226)
Proceeds from sales of loans held for sale			79,489	94,282
Gains on sales of loans held for sale			(1,443)	(1,517)
(Gains) losses on sales of other real estate owned			(17)	52
Investment securities gains	(1,273)	(150)	(1,275)	(1,919)
Increase (Decrease) in Operating Capital [Abstract]
Net (increase) decrease in accrued interest receivable			(321)	44
Net decrease in other assets			(1,506)	(2,526)
Net increase (decrease) in accrued expenses and other liabilities			(4,069)	(3,880)
Other - net			3,605	650
Net cash provided by operating activities			40,267	43,829
Investing activities:
Proceeds of other equity securities			4,681	6,994
Purchases of investments available-for-sale			(115,028)	(113,273)
Proceeds from sales of investment available-for-sale			2,251	40,863
Proceeds from maturities, calls and principal payments of investments held-to-maturity			0	5,004
Proceeds from maturities, calls and principal payments of investments available-for-sale			70,361	179,038
Net increase in loans and leases			(223,705)	(195,826)
Proceeds from the sales of other real estate owned			759	1,352
Proceeds from sales of loans previously held for investment			18,222	0
Expenditures for premises and equipment			(2,395)	(2,594)
Net cash used in investing activities			(244,854)	(78,442)
Financing activities:
Net increase in deposits			307,901	246,411
Net increase in retail repurchase agreements and federal funds purchased			2,193	8,742
Proceeds from advances from FHLB			2,220,000	1,290,000
Repayment of advances from FHLB			(2,340,000)	(1,460,000)
Retirement of subordinated debt			(30,000)	(5,000)
Proceeds from issuance of common stock			817	728
Stock tendered for payment of withholding taxes			(952)	(683)
Repurchase of common stock			0	(13,273)
Dividends paid			(12,561)	(11,622)
Net cash provided by financing activities			147,398	55,303
Net increase (decrease) in cash and cash equivalents			(57,189)	20,690
Cash and cash equivalents at beginning of period			134,125	72,882	72,882
Cash and cash equivalents at end of period	$ 76,936	$ 93,572	76,936	93,572	$ 134,125
Supplemental Disclosures:
Interest payments			12,391	11,114
Income tax payments			16,287	12,984
Transfer of Investments Held-to-maturity to Available For Sale Securities			0	203,118
Transfer from loans to residential mortgage loans held for sale			18,053	18,752
Transfers from loans to other real estate owned			$ 288	$ 0