Investment Securities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Investment [Line Items]
Amortized Cost	$ 114,401	$ 120,311
Gross Unrealized Gains	2,448	2,811
Gross Unrealized Losses	263	149
Fair Value	116,586	122,973
Amortized Cost	11	12
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	11	12
Agency mortgage-backed securities
Investment [Line Items]
Amortized Cost	21,258	22,762
Gross Unrealized Gains	393	456
Gross Unrealized Losses	22	12
Fair Value	21,629	23,206
Amortized Cost	11	12
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	11	12
Agency CMO
Investment [Line Items]
Amortized Cost	22,275	22,458
Gross Unrealized Gains	238	225
Gross Unrealized Losses	4	23
Fair Value	22,509	22,660
Agency notes and bonds
Investment [Line Items]
Amortized Cost	34,118	38,273
Gross Unrealized Gains	252	290
Gross Unrealized Losses	4	10
Fair Value	34,366	38,553
Municipal Obligations
Investment [Line Items]
Amortized Cost	32,425	32,605
Gross Unrealized Gains	1,537	1,800
Gross Unrealized Losses	221	88
Fair Value	33,741	34,317
Debt Securities
Investment [Line Items]
Amortized Cost	110,076	116,098
Gross Unrealized Gains	2,420	2,771
Gross Unrealized Losses	251	133
Fair Value	112,245	118,736
Mutual funds
Investment [Line Items]
Amortized Cost	4,325	4,213
Gross Unrealized Gains	28	40
Gross Unrealized Losses	12	16
Fair Value	$ 4,341	$ 4,237

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

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+ Details

- 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+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

For an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity. The held-to-maturity category is for those securities that the entity has the positive intent and ability to hold until maturity.

+ References

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

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+ Details

- Definition

This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

+ References+ Details

- Definition

As of the balance sheet date, the excess of fair value over carrying value (amortized cost) of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding gain.

+ References+ Details

- Definition

As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss.

+ References+ Details