Loans - Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	$ 69,411	$ 73,541
Recorded Investment With Related Allowance	97,577	117,807
Total Recorded Investment	166,988	191,348
Unpaid Contractual Principal Balance	186,023	225,471
Related Allowance	17,082	23,525
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	56,995	58,643
Recorded Investment With Related Allowance	45,921	55,995
Total Recorded Investment	102,916	114,638
Unpaid Contractual Principal Balance	107,825	131,705
Related Allowance	7,153	8,676
Consumer Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	1,067	1,010
Recorded Investment With Related Allowance	254	84
Total Recorded Investment	1,321	1,094
Unpaid Contractual Principal Balance	1,473	1,211
Related Allowance	98	82
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	2,523	3,806
Recorded Investment With Related Allowance	33,600	43,497
Total Recorded Investment	36,123	47,303
Unpaid Contractual Principal Balance	46,642	59,891
Related Allowance	6,319	11,032
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	45,671	46,872
Recorded Investment With Related Allowance	38,048	47,973
Total Recorded Investment	83,719	94,845
Unpaid Contractual Principal Balance	87,478	110,227
Related Allowance	6,246	7,874
Construction [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	11,324	11,771
Recorded Investment With Related Allowance	7,873	8,022
Total Recorded Investment	19,197	19,793
Unpaid Contractual Principal Balance	20,347	21,478
Related Allowance	907	802
Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	8,826	10,082
Recorded Investment With Related Allowance	17,802	18,231
Total Recorded Investment	26,628	28,313
Unpaid Contractual Principal Balance	30,083	32,664
Related Allowance	3,512	3,735
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance	1,067	1,010
Recorded Investment With Related Allowance	254	84
Total Recorded Investment	1,321	1,094
Unpaid Contractual Principal Balance	1,473	1,211
Related Allowance	$ 98	$ 82