XML 23 R22.htm IDEA: XBRL DOCUMENT v3.3.0.814
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Estimated value of stock-based awards, granted $ 1.9 $ 2.3
Unrecognized compensation cost related to unvested options $ 1.7  
Unvested stock-based awards expected to be recognized, weighted-average period 1 year 4 months 24 days  
Portion of stock-based awards granted from outstanding common shares 3.30% 3.00%