Consolidated Condensed Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities:
Net Income	$ 66,133	$ 60,123
Adjustments to reconcile net income to net cash provided by operating activities:
(Recovery of) provision for loan losses	(3,819)	5,648
Amortization (accretion) of investment securities, net	5,439	4,921
Provision for depreciation	6,283	5,362
Amortization (accretion) of investment securities, net	103	(186)
Amortization of prepayment penalty of long-term debt	4,618	4,522
Loan originations to be sold in secondary market	(205,576)	(163,764)
Proceeds from sale of loans in secondary market	201,616	160,593
Share-based compensation expense	1,189	704
OREO valuation adjustments	572	1,273
Gain on sale of OREO, net	(1,079)	(1,429)
Gain on sale of commercial loans held for sale	0	(756)
Bank owned life insurance income	(3,284)	(4,538)
Changes in assets and liabilities:
Increase in other assets	(15,890)	(12,461)
Decrease (increase) in other liabilities	5,443	(3,214)
Net cash provided by operating activities	57,810	53,830
Proceeds from maturity of:
Available-for-sale securities	706,634	198,418
Held-to-maturity securities	19,301	29,148
Purchases of:
Available-for-sale securities	(473,627)	(180,273)
Payments to Acquire Held-to-maturity Securities	(61,155)	(6,096)
Net loan originations, portfolio loans	(109,114)	(174,952)
Proceeds from the sale of commercial loans held for sale		900
Investments in qualified affordable housing projects	(4,555)	(4,290)
Proceeds from the sale of OREO	6,954	15,189
Payments to Acquire Life Insurance Policies	0	(10,045)
Life insurance death benefits	1,050	6,034
Purchases of premises and equipment, net	(5,516)	(9,464)
Net cash provided by (used in) investing activities	79,972	(135,431)
Financing activities:
Net increase in deposits	172,017	326,982
Net (decrease) increase in short-term borrowings	(176,028)	1,344
Proceeds from issuance of long-term debt	0	25,000
Repurchase of treasury shares	0	(4,279)
Repayment of long-term debt	0	(79,544)
Cash dividends paid	(43,232)	(43,346)
Net cash (used in) provided by financing activities	(47,243)	226,157
Increase in cash and cash equivalents	90,539	144,556
Cash and cash equivalents at beginning of year	149,459	237,699
Cash and cash equivalents at end of period	239,998	382,255
Supplemental disclosures of cash flow information:
Cash paid for interest	28,757	28,225
Cash paid for income taxes	17,460	19,820
Non cash activities:
Loans transferred to OREO	2,856	12,845
Transfers from loans to commercial loans held for sale	0	144
Securities acquired through payable	4,323	0
Affordable Housing Program Obligation, Period Increase (Decrease)	9,000	9,000
Mortgage Loans on Real Estate [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of loans in secondary market	3,938	$ 2,968
Commercial Portfolio Segment [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of commercial loans held for sale	0
Purchases of:
Proceeds from the sale of commercial loans held for sale	$ 0