Net Income (Loss) Per Common Share - Schedule of Potentially Dilutive Securities (Detail) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	12,772	12,792
Stock options [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	6,741	6,898
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	436	247
Stock appreciation rights [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	499	509
Performance shares [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations		42
Warrants [Member]
Earnings Per Share [Line Items]
Dilutive common shares excluded from net loss per common share computations	46	46