Annual report pursuant to Section 13 and 15(d)

Common Stock - Summary of Stock Options Activity (Detail)

v2.4.0.8
Common Stock - Summary of Stock Options Activity (Detail) (USD $)
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Number of Optioned Common Shares, Beginning Balance 804,781 766,328 744,913
Number of Optioned Common Shares, Option grants 239,282 172,650 101,600
Number of Optioned Common Shares, Option expired (3,061) (12,309) (22,986)
Number of Optioned Common Shares, Option exercises (3,475) (117,347) (56,228)
Number of Optioned Common Shares, Options forfeited (30,536) (4,541) (971)
Number of Optioned Common Shares, Ending Balance 1,006,991 804,781 766,328
Weighted Average Exercise Price, Beginning Balance $ 11.34 $ 9.82 $ 8.74
Weighted Average Exercise Price, Option grants $ 11.32 $ 12.97 $ 15.72
Weighted Average Exercise Price, Option expired $ 4.11 $ 9.10 $ 13.95
Weighted Average Exercise Price, Option exercises $ 3.00 $ 3.94 $ 3.88
Weighted Average Exercise Price, Options forfeited $ 13.87 $ 15.26 $ 41.91
Weighted Average Exercise Price, Ending Balance $ 11.39 $ 11.34 $ 9.82