XML 33 R81.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stock-Based Compensation - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Nov. 09, 2009
Compensation Related Costs Disclosure [Line Items]        
Common stock, capital shares reserved for future issuance       11,815,748us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Compensation expense $ 69.5us-gaap_AllocatedShareBasedCompensationExpense $ 58.4us-gaap_AllocatedShareBasedCompensationExpense $ 38.9us-gaap_AllocatedShareBasedCompensationExpense  
Unrecognized compensation expense $ 59.9us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions      
Unrecognized compensation expense, period of recognition 1 year 7 months 6 days      
Restricted Stock Units        
Compensation Related Costs Disclosure [Line Items]        
Weighted average grant date fair value of performance shares granted $ 79.73us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
$ 56.69us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
$ 43.23us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
 
Performance Shares        
Compensation Related Costs Disclosure [Line Items]        
Vesting period 3 years      
Weighted average grant date fair value of performance shares granted $ 73.85us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
$ 51.03us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
$ 45.21us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember