Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Stock Options Granted Pursuant to Equity Incentive Plans (Detail)

v2.4.0.8
Share-Based Compensation - Stock Options Granted Pursuant to Equity Incentive Plans (Detail) (USD $)
 9 Months Ended
Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Outstanding, Shares, Beginning of Period 52,696
Granted, Shares 0
Exercised, Shares (7,750)
Cancelled, Shares 0
Outstanding, Shares, End of Period 44,946
Exercisable, Shares 44,946
Outstanding, Weighted Average Exercise Price, Beginning of Period $ 9.34
Granted, Weighted Average Exercise Price $ 0
Exercised, Weighted Average Exercise Price $ 10.34
Cancelled, Weighted Average Exercise Price $ 0
Outstanding, Weighted Average Exercise Price, End of Period $ 9.16
Exercisable, Weighted Average Exercise Price $ 9.16
Outstanding, Weighted Average Remaining Contractual Term, Beginning of Period 1 year 3 months 18 days
Granted, Weighted Average Remaining Contractual Term 0 years
Exercised, Weighted Average Remaining Contractual Term 0 years
Cancelled, Weighted Average Remaining Contractual Term 0 years
Outstanding, Weighted Average Remaining Contractual Term, End of Period 6 months
Exercisable, Weighted Average Remaining Contractual Term 6 months
Outstanding, Aggregate Intrinsic Value, Beginning of Period $ 482,916
Granted, Aggregate Intrinsic Value 0
Exercised, Aggregate Intrinsic Value 140,654
Cancelled, Aggregate Intrinsic Value 0
Outstanding, Aggregate Intrinsic Value 986,477
Exercisable, Aggregate Intrinsic Value $ 986,477