Restricted Shares Issued in Conjunction with Stock Plan (Detail) (Restricted Shares, USD $)	12 Months Ended
	Dec. 31, 2012
Period 1
Class of Stock [Line Items]
Issuance Date	Feb. 05, 2010
Shares	12,520
Aggregate Market Value	$ 300,000
Period 2
Class of Stock [Line Items]
Issuance Date	Feb. 09, 2011
Shares	24,330
Aggregate Market Value	$ 600,000
Period 3
Class of Stock [Line Items]
Issuance Date	Feb. 03, 2012
Shares	25,600
Aggregate Market Value	$ 700,000