Stock Transactions and Preferred Stock Dividends - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013
Stockholders Equity Note [Line Items]
Preferred dividend required payment	$ 391,875
Preferred dividend, declared amount	$ 391,875
Preferred dividend, declared date	Apr. 26, 2013
Preferred dividend, payment date	Apr. 28, 2013