Loans - Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	$ 73,541	$ 45,203
Recorded Investment With Related Allowance	117,807	161,531
Total Recorded Investment	191,348	206,734
Unpaid Contractual Principal Balance	225,471	239,964
Related Allowance	23,525	31,013
Commercial real estate loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	58,643	33,063
Recorded Investment With Related Allowance	55,995	98,153
Total Recorded Investment	114,638	131,216
Unpaid Contractual Principal Balance	131,705	149,553
Related Allowance	8,676	16,581
Consumer loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	1,010	672
Recorded Investment With Related Allowance	84	258
Total Recorded Investment	1,094	930
Unpaid Contractual Principal Balance	1,211	1,169
Related Allowance	82	15
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	3,806	3,236
Recorded Investment With Related Allowance	43,497	46,461
Total Recorded Investment	47,303	49,697
Unpaid Contractual Principal Balance	59,891	62,183
Related Allowance	11,032	12,088
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	46,872	26,724
Recorded Investment With Related Allowance	47,973	84,151
Total Recorded Investment	94,845	110,875
Unpaid Contractual Principal Balance	110,227	125,875
Related Allowance	7,874	11,788
Construction [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	11,771	6,339
Recorded Investment With Related Allowance	8,022	14,002
Total Recorded Investment	19,793	20,341
Unpaid Contractual Principal Balance	21,478	23,678
Related Allowance	802	4,793
Residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	10,082	8,232
Recorded Investment With Related Allowance	18,231	16,659
Total Recorded Investment	28,313	24,891
Unpaid Contractual Principal Balance	32,664	27,059
Related Allowance	3,735	2,329
Home equity [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	1,010	672
Recorded Investment With Related Allowance	84	258
Total Recorded Investment	1,094	930
Unpaid Contractual Principal Balance	1,211	1,169
Related Allowance	$ 82	$ 15