XML 22 R57.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stock Plans - Summary of Performance Stock Unit Activity (Detail) (Performance Stock Unit, USD $)
3 Months Ended
Mar. 31, 2015
Performance Stock Unit
 
Shares  
Unvested Shares, Beginning Balance 143,961us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Granted 54,856us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Performance adjustments 16,447msa_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceAdjustmentInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Vested (63,164)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Unvested Shares, Ending Balance 152,100us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Weighted Average Exercise Price (dollars per share)  
Unvested Weighted Average Grant Date Fair value, Beginning Balance (dollars per share) $ 52.42us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Granted (dollars per share) $ 40.06us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Performance adjustments (dollars per share) $ 41.45msa_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceAdjustmentInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Vested (dollars per share) $ 41.66us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
Unvested Weighted Average Grant Date Fair value, Ending Balance (dollars per share) $ 51.24us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember