Allowance for Loan Losses and Recorded Investment in Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 4,549	$ 7,379
Charge-offs	(639)	(1,264)
Recoveries	36	257
Provisions	630
Ending balance	4,576	6,372
Individually evaluated for impairment	692		439
Collectively evaluated for impairment	3,884		4,110
Ending balance	4,576		4,549
Ending balance - total	145,099		160,653
Individually evaluated for impairment	28,387		27,473
Collectively evaluated for impairment	116,712		133,180
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	1,887	2,166
Charge-offs	(48)	(295)
Recoveries	3	33
Provisions	185
Ending balance	2,027	1,904
Individually evaluated for impairment			60
Collectively evaluated for impairment	2,027		1,827
Ending balance	2,027		1,887
Ending balance - total	10,392		12,939
Individually evaluated for impairment	2,408		2,356
Collectively evaluated for impairment	7,984		10,583
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	1,920	4,602
Charge-offs	(299)	(777)
Recoveries	28	138
Provisions	383
Ending balance	2,032	3,963
Individually evaluated for impairment	619		306
Collectively evaluated for impairment	1,413		1,614
Ending balance	2,032		1,920
Ending balance - total	87,309		97,547
Individually evaluated for impairment	18,115		18,352
Collectively evaluated for impairment	69,194		79,195
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	484	335
Charge-offs	(286)	(181)
Recoveries	4	25
Provisions	54
Ending balance	256	179
Individually evaluated for impairment	73		73
Collectively evaluated for impairment	183		411
Ending balance	256		484
Ending balance - total	36,509		37,829
Individually evaluated for impairment	5,915		4,933
Collectively evaluated for impairment	30,594		32,896
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	258	276
Charge-offs	(6)	(11)
Recoveries	1	61
Provisions	8
Ending balance	261	326
Collectively evaluated for impairment	261		258
Ending balance	261		258
Ending balance - total	10,889		12,338
Individually evaluated for impairment	1,949		1,832
Collectively evaluated for impairment	$ 8,940		$ 10,506