Fair Value Accounting - Gains and Losses from Fair Value Changes Included in Consolidated Statement of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Unrealized Gain/(Loss) on Assets and Liabilities Measured at Fair Value, Net	$ (314)	$ (960)
Interest Income on Securities	0	1
Interest Expense on Junior Subordinated Debt	(441)us-gaap_InterestExpenseDebt	(421)us-gaap_InterestExpenseDebt
Total Changes Included in Current-Period Earnings	(755)	(1,380)
Securities measured at fair value [Member]
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Unrealized Gain/(Loss) on Assets and Liabilities Measured at Fair Value, Net	(5)	18
Interest Income on Securities	0	1
Interest Expense on Junior Subordinated Debt	0	0
Total Changes Included in Current-Period Earnings	(5)	19
Junior subordinated debt [Member]
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Unrealized Gain/(Loss) on Assets and Liabilities Measured at Fair Value, Net	(309)	(978)
Interest Income on Securities	0	0
Interest Expense on Junior Subordinated Debt	(441)	(421)
Total Changes Included in Current-Period Earnings	$ (750)	$ (1,399)

This item represents the amount of the total realized and unrealized gains or losses for the period which are included in the statement of income (or changes in net assets); the fair value of which assets and liabilities was or is measured on a recurring basis using significant unobservable inputs (Level 3).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those liabilities still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Amount of operating dividend and interest income, including amortization and accretion of premiums and discounts, on securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24721-111560

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 2, 3

-Article 9

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.2,3)

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

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-Paragraph 8

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