Loans And Leases (Summary Of Loan And Lease Portfolio Aging By Class Of Loan) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	$ 28,187		$ 42,023
60-89 Days Past Due and Accruing	15,994		32,093
Non-accrual	4,864		1,257
Financing Receivable, Recorded Investment, Nonaccrual Status	177,878		195,150
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	226,923		270,523
Current	12,287,554		11,793,533
Recorded investment in loans and leases	12,514,477	[1]	12,064,056	[1]
1-4 family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	12,259		16,955
60-89 Days Past Due and Accruing	8,851		8,250
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	85,879		94,853
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	106,989		120,058
Current	3,210,931		3,142,220
Recorded investment in loans and leases	3,317,920		3,262,278
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	0		0
60-89 Days Past Due and Accruing	0		360
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	390		823
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	390		1,183
Current	42,492		38,535
Recorded investment in loans and leases	42,882		39,718
Home equity loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	10,407		17,745
60-89 Days Past Due and Accruing	5,318		6,993
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	45,504		49,516
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	61,229		74,254
Current	2,312,883		2,396,944
Recorded investment in loans and leases	2,374,112		2,471,198
Liquidating portfolio-home equity loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	1,707		2,063
60-89 Days Past Due and Accruing	1,089		1,626
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	6,554		8,200
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	9,350		11,889
Current	100,537		111,760
Recorded investment in loans and leases	109,887		123,649
Other consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	434		338
60-89 Days Past Due and Accruing	81		195
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	180		135
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	695		668
Current	55,335		43,446
Recorded investment in loans and leases	56,030		44,114
Commercial non-mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	2,406		2,248
60-89 Days Past Due and Accruing	622		552
Non-accrual	4,239		347
Financing Receivable, Recorded Investment, Nonaccrual Status	17,453		17,547
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	24,720		20,694
Current	2,557,866		2,386,775
Recorded investment in loans and leases	2,582,586		2,407,469
Asset-based loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	0		0
60-89 Days Past Due and Accruing	0		0
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	0		0
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	0		0
Current	613,801		505,717
Recorded investment in loans and leases	613,801		505,717
Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	552		1,081
60-89 Days Past Due and Accruing	0		13,784
Non-accrual	625		910
Financing Receivable, Recorded Investment, Nonaccrual Status	15,883		15,658
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	17,060		31,433
Current	2,788,443		2,617,213
Recorded investment in loans and leases	2,805,503		2,648,646
Commercial construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	0		0
60-89 Days Past Due and Accruing	0		0
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	49		49
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	49		49
Current	161,252		114,097
Recorded investment in loans and leases	161,301		114,146
Residential development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	0		0
60-89 Days Past Due and Accruing	0		0
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	4,317		5,044
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	4,317		5,044
Current	20,311		22,766
Recorded investment in loans and leases	24,628		27,810
Equipment Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	422		1,593
60-89 Days Past Due and Accruing	33		333
Non-accrual	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	1,669		3,325
Financing Receivable, Recorded Investment, Past Due and Non-Accrual	2,124		5,251
Current	423,703		414,060
Recorded investment in loans and leases	$ 425,827		$ 419,311

[1] Loans and leases include net deferred fees and unamortized premiums of $13.2 million and $12.7 million at September 30, 2013 and December 31, 2012, respectively.