Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 79,164	$ 72,475
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,516	6,551
Provision for loan losses	18,043	12,253
(Gain) loss on other real estate owned	(991)	210
Deferred tax expense	30,829	14,790
Increase in cash surrender value of life insurance contracts	(3,772)	(3,346)
Loss on sale of business		1,145
Net decrease in loans held for sale	5,714	18,172
Net amortization of securities premium/discount	7,009	8,453
Amortization of intangible assets	5,138	5,618
Stock-based compensation expense	5,181	4,883
Contribution to pension plan	(100,000)
Decrease in interest payable and other liabilities	(15,478)	(32,568)
Decrease in payable to FDIC for loan servicing		(11,107)
(Increase) decrease in other assets	(23,335)	6,821
Other, net	(1,595)	144
Net cash provided by operating activities	13,423	104,494
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of securities available for sale	55,596	80,155
Purchases of securities available for sale	(1,502)	(142,052)
Proceeds from maturities of securities held to maturity	79,533	93,408
Purchases of securities held to maturity		(134,020)
Net (increase) decrease in short-term investments	(52,668)	30,843
Proceeds from sales of loans and leases	42,059	12,211
Net increase in loans	(148,073)	(196,328)
Purchases of property and equipment	(12,435)	(7,904)
Proceeds from sales of property and equipment	115	42
Proceeds from sales of other real estate	4,613	1,641
Final cash settlement for acquisition of business	(1,112)
Proceeds from the sale of business, net of cash sold		77,081
Other, net	(8,978)	(8,915)
Net cash used in investing activities	(42,852)	(193,838)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	230,109	232,638
Net decrease in short-term borrowings	(200,393)	(251,793)
Repayments of long-term debt	(75)	(5,268)
Net proceeds from issuance of long-term debt		83
Dividends paid	(23,581)	(20,881)
Payroll tax remitted on net share settlement of equity awards	(688)	(142)
Proceeds from exercise of stock options		782
Proceeds from dividend reinvestment and stock purchase plans	879	837
Net cash provided by (used in) financing activities	6,251	(43,744)
NET DECREASE IN CASH AND DUE FROM BANKS	(23,178)	(133,088)
CASH AND DUE FROM BANKS, BEGINNING	383,372	386,948
CASH AND DUE FROM BANKS, ENDING	360,194	253,860
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 4,273	$ 1,305