Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Schedule of Restricted Stock Awards under 2013 Plan (Detail)

v2.4.1.9
Share-Based Compensation - Schedule of Restricted Stock Awards under 2013 Plan (Detail) (USD $)
3 Months Ended
Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Number of Shares, Restricted stock at beginning of period 173,222us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Number of Shares, Restricted stock granted 3,850us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Number of Shares, Restricted stock vested (2,000)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Number of Shares, Restricted stock at end of period 175,072us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Weighted-Average Grant Date Fair Value Per Share, Restricted stock at beginning of period $ 19.58us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Weighted-Average Grant Date Fair Value Per Share, Restricted stock granted $ 20.33us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Weighted-Average Grant Date Fair Value Per Share, Restricted stock vested $ 24.45us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Weighted-Average Grant Date Fair Value Per Share, Restricted stock at end of period $ 19.55us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue