Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Restricted Stock Unit Award Activity (Detail)

v2.4.0.8
Common Stock - Summary of Restricted Stock Unit Award Activity (Detail) (Restricted stock unit awards [Member], USD $)
6 Months Ended
Jun. 30, 2014
Restricted stock unit awards [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Stock Awards, Beginning Balance 356,589
Stock Awards, Granted 766,300
Stock Awards, Vested (49,348)
Stock Awards, Forfeited or expired (202,946)
Stock Awards, Ending Balance 870,595
Weighted-Average Grant Date Fair Value, Beginning Balance $ 12.06
Weighted-Average Grant Date Fair Value, Granted $ 6.72
Weighted-Average Grant Date Fair Value, Vested $ 11.84
Weighted-Average Grant Date Fair Value, Forfeited or expired $ 12.15
Weighted-Average Grant Date Fair Value, Ending Balance $ 7.35