Investment Securities - Securities with Other-than-Temporary-Impairment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2015
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Amortized Cost		$ 4,499
Amount of other-than-temporary-impairment recognized in earnings	100
Life-to date		5,785
Reg Div Funding 2004 [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Vintage		2004
Lowest Credit Rating		D
Amortized Cost		3,769
Life-to date		5,685
Limited Partnership [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Amortized Cost		730
Amount of other-than-temporary-impairment recognized in earnings	100
Life-to date		$ 100

Available for sale securities cumulative amount of other than temporary impairment recognized in earnings.

No definition available.

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- Definition

Debt issuance year.

+ References

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- Definition

Debt securities lowest credit rating.

+ References

No definition available.

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- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8B

-URI http://asc.fasb.org/extlink&oid=27724398&loc=SL6284393-111563

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