Loans And Leases (Summary Of Loan And Lease Portfolio Aging By Class Of Loan) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	$ 28,627		$ 35,409
60-89 Days Past Due and Accruing	12,220		13,786
90 Days Past Due and Accruing	50		4,540
Non-accrual	132,186		163,228
Total Past Due and Non-accrual	173,083		216,963
Current	13,765,339		12,519,246
Total Loans and Leases	13,938,422	[1]	12,736,209	[1]
Total recorded investment of TDRs	320,170		341,898
Residential TDR CH 7 Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total recorded investment of TDRs	17,600
1-4 family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	11,521	[2]	11,721
60-89 Days Past Due and Accruing	5,931	[2]	6,839
90 Days Past Due and Accruing	0	[2]	0
Non-accrual	66,156	[2]	81,520
Total Past Due and Non-accrual	83,608	[2]	100,080
Current	3,436,023	[2]	3,271,479
Total Loans and Leases	3,519,631	[2]	3,371,559
Home equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	11,516	[2]	15,332
60-89 Days Past Due and Accruing	5,161	[2]	5,120
90 Days Past Due and Accruing	0	[2]	0
Non-accrual	40,025	[2]	51,788
Total Past Due and Non-accrual	56,702	[2]	72,240
Current	2,424,584	[2]	2,410,953
Total Loans and Leases	2,481,286	[2]	2,483,193
Other consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	720		462
60-89 Days Past Due and Accruing	425		193
90 Days Past Due and Accruing	0		0
Non-accrual	281		140
Total Past Due and Non-accrual	1,426		795
Current	74,722		60,543
Total Loans and Leases	76,148		61,338
Commercial non-mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	1,971		3,208
60-89 Days Past Due and Accruing	156		984
90 Days Past Due and Accruing	50		4,305
Non-accrual	6,449		10,946
Total Past Due and Non-accrual	8,626		19,443
Current	3,088,656		2,712,870
Total Loans and Leases	3,097,282		2,732,313
Asset-based [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
90 Days Past Due and Accruing	0		0
Non-accrual	0		0
Total Past Due and Non-accrual	0		0
Current	663,163		560,931
Total Loans and Leases	663,163		560,931
Commercial real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	2,348		4,387
60-89 Days Past Due and Accruing	397		587
90 Days Past Due and Accruing	0		235
Non-accrual	15,038		13,456
Total Past Due and Non-accrual	17,783		18,665
Current	3,310,765		2,842,637
Total Loans and Leases	3,328,548		2,861,302
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
90 Days Past Due and Accruing	0		0
Non-accrual	3,659		4,237
Total Past Due and Non-accrual	3,659		4,237
Current	230,954		200,886
Total Loans and Leases	234,613		205,123
Finance Leases Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due and Accruing	551		299
60-89 Days Past Due and Accruing	150		63
90 Days Past Due and Accruing	0		0
Non-accrual	578		1,141
Total Past Due and Non-accrual	1,279		1,503
Current	536,472		458,947
Total Loans and Leases	$ 537,751		$ 460,450

[1] Loans and leases include net deferred fees and unamortized premiums of $10.6 million and $13.3 million at December 31, 2014 and December 31, 2013, respectively.

[2] A total of $17.6 million residential and consumer loans was reclassified from non-accrual to accrual status as a result of updated regulatory guidance issued in the first quarter of 2014.