Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Oct. 31, 2015	Sep. 30, 2015
Subsequent Event [Line Items]
Stock issued during period, shares		10,000,000
Subsequent Event | Series N-1 Preferred Stock
Subsequent Event [Line Items]
Stock issued during period, shares	50,000
Proceed from issuance of preferred stock	$ 50.0
Issuance Costs	$ 3.5
Conversion Price per Share	$ 1.25
Preferred stock, description of liquidation preference	Each share of Series N-1 Preferred Stock was entitled to a liquidation preference equal to the initial stated value of $1,000 per share of Series N-1 Preferred Stock, plus any declared and unpaid dividends, and any other payments that may be due on such shares, before any distribution of assets may be made to holders of capital stock ranking junior to the Series N-1 Preferred Stock.
Preferred stock stated value	$ 1,000
Number of preferred stock converted to common stock	50,000
Conversion of preferred stock to common stock (in shares)	40,000,000
Subsequent Event | Series N-1 Preferred Stock | Underwriting Commissions and Discounts
Subsequent Event [Line Items]
Issuance Costs	$ 3.0