Common Stock Offering (Details Textual) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012
Issuance of common stock, net of issuance costs (in shares)	1,300,000
Sale of Stock, Price Per Share				$ 24.75
Proceeds From Issuance Of Common Stock	$ 35,000,000	$ 35,042,235	$ 0
Over Allotment Option [Member]
Sale of Stock, Number of Shares Issued in Transaction	195,000