Series C Convertible Preferred Stock - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2011	Mar. 31, 2011 Series C Preferred Stock	Dec. 31, 2013 Series C Preferred Stock Installment
Preferred Stock [Line Items]
Preferred shares issued		7,000
Initial stated value per preferred share		$ 10,000
Proceeds from the sale of Series C Convertible Preferred Stock	$ 61,403,000	$ 64,013,000
Agent fees and offering costs		5,987,000
Percentage of dividend payable			8.00%
Number of equal quarterly installments			9
Installments start date			Sep. 01, 2011
Installments end date			Sep. 01, 2013
Preferred share plus accumulated and unpaid dividends			$ 10,000
Conversion price of convertible preference stock			$ 15.83
Stock issued upon conversion of preferred stock (in shares)			954,000