Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

Allowance for Credit Losses and Loan Portfolio by Loan Segment (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 6,251		$ 7,938
Collectively evaluated for impairment	63,242		62,960
Total Allowance for Loan Losses	69,493	70,143	70,898	73,074	77,133	82,977
Individually evaluated for impairment	79,965		83,319
Collectively evaluated for impairment	2,756,359		2,630,096
Loans	2,836,324		2,713,415
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	1,775		4,701
Collectively evaluated for impairment	20,549		13,030
Total Allowance for Loan Losses	22,324	17,791	17,731	19,644	23,715	32,508
Individually evaluated for impairment	16,286		18,793
Collectively evaluated for impairment	725,073		657,760
Loans	741,359		676,553
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	4,157		2,504
Collectively evaluated for impairment	27,256		35,415
Total Allowance for Loan Losses	31,413	35,133	37,919	37,085	38,668	36,341
Individually evaluated for impairment	54,773		51,980
Collectively evaluated for impairment	1,279,891		1,224,031
Loans	1,334,664		1,276,011
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Collectively evaluated for impairment	2,629		2,902
Total Allowance for Loan Losses	2,629	2,431	2,902	3,037	2,859	3,622
Collectively evaluated for impairment	77,171		84,172
Loans	77,171		84,172
Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	319		733
Collectively evaluated for impairment	12,808		11,610
Total Allowance for Loan Losses	13,127	14,788	12,343	13,299	11,877	10,408
Individually evaluated for impairment	8,906		12,546
Collectively evaluated for impairment	671,254		660,578
Loans	680,160		673,124
Finance Lease
Financing Receivable, Allowance for Credit Losses [Line Items]
Collectively evaluated for impairment			3
Total Allowance for Loan Losses			3	9	14	98
Collectively evaluated for impairment	2,970		3,555
Loans	$ 2,970		$ 3,555