Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Operating Activities:
Net income	$ 39,713	$ 30,868	$ 71,979	$ 59,312
Adjustment to reconcile net income to net cash provided by operating activities:
Provision for credit losses	(5,000)		(10,000)
Depreciation and amortization			13,411	13,569
Deferred taxes				(1,939)
Amortization of intangibles	1,061	1,148	2,093	2,206
Amortization of debt securities premium and discount, net			6,503	6,724
Share-based compensation expense			3,904	1,089
Security gains, net	(41)	(5)	(55)	(1)
Net deferred loan origination expense			(3,295)	(3,427)
Excess tax benefit from exercise of stock options			702	1,216
(Increase) decrease in interest receivable			920	1,453
Increase (decrease) in interest payable			94	(910)
Realized gain on mortgages sold			(21,672)	(15,477)
Proceeds from mortgages sold			687,076	496,915
Origination of mortgages held for sale			(728,269)	(488,120)
Loss on other real estate owned, net			2,634	5,587
Increase in bank-owned life insurance			(3,649)	(3,733)
Decrease in prepaid pension asset				2,829
Other, net			12,949	17,352
Net cash provided by operating activities			35,325	94,645
Investing activities:
Proceeds from calls and maturities of available-for-sale securities			151,206	275,038
Proceeds from sales of available-for-sale securities			1,110
Purchases of available-for-sale securities			(261,356)	(125,055)
Net (increase) decrease in loans and leases			(290,005)	(395,544)
Purchases of premises and equipment			(12,818)	(8,905)
Proceeds from sale of premises and equipment			139	219
Purchase of bank-owned life insurance, net of proceeds from death benefits			2,742	1,206
Acquisition of Insurance Agency				(5,060)
Proceeds from sale of other real estate owned, net			11,468	17,348
Other, net			(12)	(12)
Net cash used in investing activities			(397,526)	(240,765)
Financing activities:
Net increase (decrease) in deposits			162,622	(103,422)
Net increase (decrease) in short-term debt and other liabilities			76,806	(26,590)
Advances of long-term debt				8,000
Repayment of advances of long-term debt			(4,186)	(3,879)
Redemption of Junior Subordinated Debt				(8,248)
Issuance of common stock			5,168	9,461
Repurchase of common stock			(2,288)	(675)
Excess tax benefit from exercise of stock options			(702)	(1,216)
Payment of cash dividends			(14,490)	(9,589)
Net cash (used in) provided by financing activities			222,930	(136,158)
Increase (decrease) in cash and cash equivalents			(139,271)	(282,278)
Cash and cash equivalents at beginning of period			357,250	528,423	$ 528,423
Cash and cash equivalents at end of period	$ 217,979	$ 246,145	$ 217,979	$ 246,145	$ 357,250