Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net Income	$ 15,770	$ 12,889
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	780	786
Depreciation of premises and equipment, net	1,903	1,519
Amortization of fees and discounts, net	3,895	3,068
Amortization of intangible assets	549	466
Decrease (increase) in accrued interest receivable	48	(222)
(Increase) decrease in other assets	(3,534)	(4,275)
Origination of loans held-for-sale	(72,474)	(83,411)
Proceeds from sales of loans held-for-sale	77,834	66,225
Gain on mortgage banking activities, net	(1,654)	(1,703)
Gain on sale of securities, net	(305)	(451)
Stock-based compensation expense	758	1,364
Excess tax benefit from stock-based compensation	(419)	(522)
Increase in accrued interest payable	539	617
(Decrease) increase in other liabilities	(7,930)	(3,834)
Loss (gain) on sale of other real estate owned and valuation adjustments, net	76	75
Deferred income tax expense	3,293	2,389
Increase in value of bank-owned life insurance	(231)	(203)
Increase in capitalized interest, net, on reverse mortgage loans	(1,193)	(1,236)
Net cash provided by (used for) operating activities	17,705	(6,459)
Investing activities:
Purchases of investment securities held-to-maturity	(3,329)
Repayments of investment securities held-to-maturity	1,335
Maturities and calls of investment securities held-to-maturity	400
Sale of investment securities available-for-sale	38,932	35,553
Purchases of investment securities available-for-sale	(91,963)	(94,300)
Repayments of investment securities available-for-sale	15,463	19,399
Maturities of investment securities available for sale		1,761
Repayments on reverse mortgages	1,582	3,743
Disbursements for reverse mortgages	(844)	(244)
Net increase in loans	(30,748)	(36,108)
Net (increase) decrease in stock of FHLB	(192)	(4,377)
Sales of assets acquired through foreclosure, net	1,442	1,184
Investment in premises and equipment, net	(1,234)	(817)
Net cash used for investing activities	(69,156)	(74,206)
Financing activities:
Net increase in demand and saving deposits	35,907	(103,384)
(Decrease) increase in time deposits	(26,072)	(26,970)
Increase in brokered deposits	43,353	6,668
(Decrease) increase in loan payable	(407)	21
Receipts from FHLB advances	28,349,212	14,439,318
Repayments of FHLB advances	(28,310,900)	(14,221,453)
Receipts from federal funds purchased and securities sold under agreement to repurchase	8,710,770	6,981,250
Repayments of federal funds purchased and securities sold under agreement to repurchase	(8,711,445)	(6,995,625)
Dividends paid	(1,783)	(1,405)
Issuance of common stock and exercise of common stock options	241	498
Purchase of treasury stock	(8,995)	(879)
Excess tax benefit from stock-based compensation	419	522
Net cash provided by financing activities	80,300	78,561
Increase (decrease) in cash and cash equivalents	28,849	(2,104)
Cash and cash equivalents at beginning of period	561,179	508,039
Cash and cash equivalents at end of period	590,028	505,935
Supplemental Disclosure of Cash Flow Information:
Cash paid for interest during the period	4,151	3,417
Cash paid for income taxes, net	9,554	8,566
Loans transferred to other real estate owned	417	1,613
Loans transferred to portfolio from held-for-sale at fair value	1,510	211
Net change in accumulated other comprehensive income	10,758	4,101
Non-cash goodwill adjustments, net	$ (358)	$ 173