Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary Of Impaired Loans Evaluated For Impairment By Loan Class) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Related Allowance	$ 14,329
Recorded Investment	176,298	233,014	204,545
Unpaid Principal Balance	205,924	256,725	231,340
Average Recorded Investment	181,301	247,500	222,076
Interest Income Recognized	7,129	9,301	10,819
Home equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,347	8,254	7,270
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	5,559	8,923	7,313
Related Allowance	2,447	3,011	2,569
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,468	8,572	7,282
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	187	352	271
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	5,805	4,864	7,320
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	7,215	5,494	8,758
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	5,568	4,931	8,164
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	221	162	376
Residential real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,999	13,578	6,420
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	6,533	14,220	6,931
Related Allowance	856	3,244	1,169
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,418	13,507	6,424
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	170	448	226
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	10,482	5,118	8,390
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	12,841	5,374	9,189
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,805	5,392	9,069
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	292	118	337
Indirect consumer
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	12	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	13	0
Related Allowance	0	1	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	13	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	1	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	79	57	53
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	88	71	61
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	70	67	65
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	7	5	6
Consumer and other
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	667	1,349	502
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	668	1,349	502
Related Allowance	252	480	142
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	661	1,351	502
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	25	64	26
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,028	233	1,104
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,564	237	1,558
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,058	248	1,507
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	72	11	94
Commercial and industrial | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	10,599	11,271	11,010
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	12,226	13,484	12,562
Related Allowance	3,915	2,615	1,982
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	11,155	13,623	13,312
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	558	670	881
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	10,858	25,019	20,270
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	15,320	28,581	27,574
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	13,841	27,829	23,877
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	683	1,076	1,259
Franchise | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	1,792	1,792
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	1,792	1,792
Related Allowance	0	386	1,259
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	1,792	1,792
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	91	122
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Mortgage warehouse line of credit | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Community Advantage - homeowners association | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Aircraft | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	428	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	428	0
Related Allowance	0	95	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	428	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	22	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Asset-based lending | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	2,287	306	511
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	2,296	1,624	511
Related Allowance	1,549	72	55
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,299	558	484
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	86	67	26
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	76	22	25
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,416	57	1,362
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	87	81	252
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	57	5	76
Tax exempt | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Leases | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Other | Commercial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Residential construction | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	377	2,637	2,007
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	377	2,712	2,007
Related Allowance	49	540	389
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	379	2,637	2,007
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	19	102	98
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	3,267	3,603	4,085
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	3,426	3,719	4,440
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	3,954	4,389	4,507
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	122	134	143
Commercial construction | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	9,577	4,184	1,865
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	9,577	4,184	1,865
Related Allowance	103	743	70
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	10,051	4,160	1,865
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	284	153	78
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	8,705	9,868	12,263
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	13,939	10,466	13,395
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	10,899	10,937	13,635
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	564	332	540
Land | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	12,161	13,689	12,184
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	15,486	15,459	12,860
Related Allowance	947	1,576	1,414
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	12,321	13,986	12,673
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	445	460	483
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	4,980	13,330	12,163
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	6,094	17,331	17,141
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	3,869	15,866	14,646
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	181	648	906
Office | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	7,322	7,366	5,829
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	7,376	9,851	5,887
Related Allowance	111	802	622
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	7,426	7,998	5,936
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	207	355	246
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,329	9,463	8,939
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	9,324	10,368	9,521
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	8,242	9,627	9,432
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	358	339	437
Industrial | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	3,352	752	1,150
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	3,417	804	1,200
Related Allowance	177	295	224
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3,402	778	1,208
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	124	34	75
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,668	3,080	3,598
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	7,833	3,164	3,776
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	7,772	3,115	3,741
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	357	107	181
Retail | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	18,583	17,933	13,240
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	18,662	18,060	13,314
Related Allowance	1,942	1,257	343
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	18,859	18,024	13,230
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	564	626	584
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	6,230	16,610	18,073
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	6,549	16,876	18,997
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	6,270	17,070	19,067
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	257	613	892
Multi-family | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	3,715	5,588	3,954
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	4,188	5,588	3,954
Related Allowance	260	859	348
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3,809	5,598	3,972
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	143	213	157
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,149	1,926	2,817
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,983	2,672	4,494
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,868	2,371	4,120
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	115	87	222
Mixed use and other | Commercial real-estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	19,451	30,921	22,249
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	19,711	32,005	23,166
Related Allowance	1,721	3,842	2,989
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	18,569	31,582	23,185
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	669	1,145	1,165
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,205	19,761	15,462
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	11,256	21,819	17,210
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	8,181	20,970	16,122
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	362	861	912
Commercial insurance loans | Premium finance receivables
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Life insurance loans | Premium finance receivables
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0
Purchased life insurance loans | Premium finance receivables
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	$ 0	$ 0	$ 0