Fair Value Of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Of Financial Instruments [Abstract]

Fair value of financial instruments [Table Text Block]

	Fair Value Hierarchy Level	March 31, 2017				December 31, 2016
(In thousands)		Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Financial Assets
Loans:
Business	Level 3	$	4,888,011	$	4,897,223	$	4,776,365	$	4,787,469
Real estate - construction and land	Level 3	846,904		856,027		791,236		800,426
Real estate - business	Level 3	2,710,595		2,723,734		2,643,374		2,658,093
Real estate - personal	Level 3	2,013,437		2,006,535		2,010,397		2,005,227
Consumer	Level 3	1,975,521		1,957,407		1,990,801		1,974,784
Revolving home equity	Level 3	396,542		397,307		413,634		414,499
Consumer credit card	Level 3	736,766		754,362		776,465		794,856
Overdrafts	Level 3	4,733		4,733		10,464		10,464
Loans held for sale	Level 2	15,559		15,559		14,456		14,456
Investment securities:
Available for sale	Level 1	939,499		939,499		945,871		945,871
Available for sale	Level 2	8,715,393		8,715,393		8,686,650		8,686,650
Available for sale	Level 3	17,083		17,083		16,682		16,682
Trading	Level 2	20,200		20,200		22,225		22,225
Non-marketable	Level 3	101,688		101,688		99,558		99,558
Federal funds sold	Level 1	2,205		2,205		15,470		15,470
Securities purchased under agreements to resell	Level 3	725,000		728,705		725,000		728,179
Interest earning deposits with banks	Level 1	120,234		120,234		272,275		272,275
Cash and due from banks	Level 1	416,161		416,161		494,690		494,690
Derivative instruments	Level 2	8,925		8,925		13,146		13,146
Derivative instruments	Level 3	960		960		420		420
Assets held in trust for deferred compensation plan	Level 1	11,583		11,583		10,261		10,261
Financial Liabilities
Non-interest bearing deposits	Level 1	$	7,237,815	$	7,237,815	$	7,429,398	$	7,429,398
Savings, interest checking and money market deposits	Level 1	11,439,078		11,439,078		11,430,789		11,430,789
Time open and certificates of deposit	Level 3	2,414,960		2,406,892		2,240,908		2,235,218
Federal funds purchased	Level 1	340,195		340,195		52,840		52,840
Securities sold under agreements to repurchase	Level 3	980,954		981,155		1,671,065		1,671,227
Other borrowings	Level 3	101,975		103,564		102,049		104,298
Derivative instruments	Level 2	7,260		7,260		13,177		13,177
Derivative instruments	Level 3	138		138		162		162
Liabilities held in trust for deferred compensation plan	Level 1	11,583		11,583		10,261		10,261