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Securities - Maturities of securities and their weighted average yields (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	3.74%
Amortized Cost	$ 130,370,000	$ 134,664,000
Available for sale securities/Fair Value	123,793,000	138,314,000
Due in 2013 [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	6.94%
Amortized Cost	355,000
Available for sale securities/Fair Value	355,000
Due in 2014 through 2018 [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	4.99%
Amortized Cost	4,651,000
Available for sale securities/Fair Value	4,751,000
Due in 2019 through 2023 [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	3.17%
Amortized Cost	31,126,000
Available for sale securities/Fair Value	29,918,000
Due in 2024 and beyond [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	3.64%
Amortized Cost	79,480,000
Available for sale securities/Fair Value	72,893,000
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	5.19%
Amortized Cost	13,382,000	20,182,000
Available for sale securities/Fair Value	14,511,000	21,996,000
Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Yield	2.09%
Amortized Cost	1,376,000	1,354,000
Available for sale securities/Fair Value	$ 1,365,000	$ 1,405,000

X

- Definition

Weighted average yield of securities portfolio.

+ References

No definition available.

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X

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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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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