Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Thousands		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jan. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Common stock issued, shares	70,486,173	70,486,173		70,109,488
Common stock, capital shares reserved for future issuance	7,702,729	7,702,729
Series A Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock dividends issued		1,813
Dividends in arrears	$ 9
Performance Units [Member]
Class of Stock [Line Items]
Common stock issued, shares			54,801