Loans and Leases and the Allowance for Credit Losses - Interest Income Recognized on Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	$ 764,080	$ 894,854
Interest Income Recognized, Total	5,705	6,581
Interest Income Recognized, Cash Basis	3,516	4,264
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	214,618	134,306
Interest Income Recognized, Total	604	548
Interest Income Recognized, Cash Basis	604	548
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	153,070	185,425
Interest Income Recognized, Total	1,102	926
Interest Income Recognized, Cash Basis	1,102	926
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	73,151	101,253
Interest Income Recognized, Total	63	74
Interest Income Recognized, Cash Basis	63	74
Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	25,540	87,292
Interest Income Recognized, Total	55	1,087
Interest Income Recognized, Cash Basis	55	1,087
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	104,490	174,168
Interest Income Recognized, Total	1,446	1,400
Interest Income Recognized, Cash Basis	910	902
Residential Alt-A [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	125,654	139,651
Interest Income Recognized, Total	1,610	1,626
Interest Income Recognized, Cash Basis	647	559
Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	19,683	15,676
Interest Income Recognized, Total	201	121
Interest Income Recognized, Cash Basis	48	29
Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	29,013	39,383
Interest Income Recognized, Total	450	625
Interest Income Recognized, Cash Basis	54	87
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	18,861	17,700
Interest Income Recognized, Total	174	174
Interest Income Recognized, Cash Basis	$ 33	$ 52

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5212-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5258-111524

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

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- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

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