Allowance for Loan Losses - Non Homogenous Loans and Leases (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	$ 301,291	$ 286,778
Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	11,414	13,815
Land, Farmland, Ag Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	16,764	14,002
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	142,342	136,879
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	50,178	42,094
Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	80,593	79,988
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	256,482	235,522
Pass [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	4,854	10,586
Pass [Member] | Land, Farmland, Ag Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	15,159	13,063
Pass [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	115,788	107,065
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	49,466	39,666
Pass [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	71,215	65,142
Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	24,157	30,370
Watch [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	6,548	3,215
Watch [Member] | Land, Farmland, Ag Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	775	0
Watch [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	12,406	17,137
Watch [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	17	2,256
Watch [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	4,411	7,762
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	10,208	9,888
Special Mention [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	0	0
Special Mention [Member] | Land, Farmland, Ag Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	0	0
Special Mention [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	8,122	6,479
Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	540	0
Special Mention [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	1,546	3,409
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	10,444	10,998
Substandard [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	12	14
Substandard [Member] | Land, Farmland, Ag Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	830	939
Substandard [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	6,026	6,198
Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	155	172
Substandard [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Non-homogenous loans and leases	$ 3,421	$ 3,675