Net Income (Loss) Per Common Share - Schedule of Potentially Dilutive Securities (Detail) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	13,033	12,778
Stock options [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	7,049	7,348
Convertible notes [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	5,050	5,050
Restricted stock units [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	446	250
Stock appreciation rights [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	442
Performance shares [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations		84
Warrants [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	46	46