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 $)
 6 Months Ended
Jun. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Outstanding, Shares, Beginning of Period 52,696
Granted, Shares 0
Exercised, Shares (750)
Cancelled, Shares 0
Outstanding, Shares, End of Period 51,946
Exercisable, Shares 51,946
Outstanding, Weighted Average Exercise Price, Beginning of Period $ 9.34
Granted, Weighted Average Exercise Price $ 0
Exercised, Weighted Average Exercise Price $ 7.89
Cancelled, Weighted Average Exercise Price $ 0
Outstanding, Weighted Average Exercise Price, End of Period $ 9.36
Exercisable, Weighted Average Exercise Price $ 9.36
Outstanding, Weighted Average Remaining Contractual Term, Beginning of Period 1 year 3 months 18 days
Exercised, Weighted Average Remaining Contractual Term 0 years
Outstanding, Weighted Average Remaining Contractual Term, End of Period 9 months 18 days
Exercisable, Weighted Average Remaining Contractual Term 9 months 18 days
Outstanding, Aggregate Intrinsic Value, Beginning of Period $ 482,916
Exercised, Aggregate Intrinsic Value 10,770
Outstanding, Aggregate Intrinsic Value 761,181
Exercisable, Aggregate Intrinsic Value $ 761,181