Loans And Leases (Recorded Investment In Loans And Leases) (Detail) (USD $)	Sep. 30, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated for impairment	$ 339,506,000	[1]	$ 352,505,000	[1]
Collectively evaluated for impairment	13,212,647,000	[1]	12,383,704,000	[1]
Total Loans and Leases	13,552,153,000	[1]	12,736,209,000	[1]
Less: Accrued interest	38,651,000	[1]	36,433,000	[1]
Loans and leases	13,513,502,000	[1]	12,699,776,000	[1]
Unamortized premiums	14,500,000		13,300,000
Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated for impairment	144,355,000		142,871,000
Collectively evaluated for impairment	3,321,447,000		3,228,688,000
Total Loans and Leases	3,465,802,000		3,371,559,000
Less: Accrued interest	10,448,000		10,134,000
Loans and leases	3,455,354,000		3,361,425,000
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated for impairment	51,503,000		52,179,000
Collectively evaluated for impairment	2,538,505,000		2,492,353,000
Total Loans and Leases	2,590,008,000		2,544,532,000
Less: Accrued interest	8,108,000		7,844,000
Loans and leases	2,581,900,000		2,536,688,000
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated for impairment	41,329,000		52,199,000
Collectively evaluated for impairment	3,602,406,000		3,241,045,000
Total Loans and Leases	3,643,735,000		3,293,244,000
Less: Accrued interest	11,744,000		10,393,000
Loans and leases	3,631,991,000		3,282,851,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated for impairment	100,560,000	[2]	105,046,000	[2]
Collectively evaluated for impairment	3,261,898,000	[2]	2,961,378,000	[2]
Total Loans and Leases	3,362,458,000	[2]	3,066,424,000	[2]
Less: Accrued interest	8,351,000	[2]	8,062,000	[2]
Loans and leases	3,354,107,000	[2]	3,058,362,000	[2]
Equipment financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Individually evaluated for impairment	1,759,000		210,000
Collectively evaluated for impairment	488,391,000		460,240,000
Total Loans and Leases	490,150,000		460,450,000
Less: Accrued interest	0		0
Loans and leases	$ 490,150,000		$ 460,450,000

[1] Loans and leases include net deferred fees and unamortized premiums of $14.5 million and $13.3 million at September 30, 2014 and December 31, 2013, respectively.

[2] Includes certain loans individually evaluated for impairment under the Company's loan policy that were deemed not to be impaired at both September 30, 2014 and December 31, 2013.