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Securities - Maturities of securities and their weighted average yields (Detail) (USD $) | Sep. 30, 2013 | Dec. 31, 2012
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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

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- 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 + Details
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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 + Details
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