Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2015
SpaceClaim Corporation [Member] | Developed Software
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	10 years
SpaceClaim Corporation [Member] | Customer Relationships
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	6 years
SpaceClaim Corporation [Member] | Trade Names
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	6 years
SpaceClaim Corporation [Member] | Contract Backlog
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	6 years
SpaceClaim Corporation [Member] | Non-Compete Agreements
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	2 years
EVEN-Evolutionary Engineering Aktiengesellschaft [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	5 years
Maximum [Member] | Trade Names
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	10 years
Maximum [Member] | Reaction Design [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	11 years
Minimum [Member] | Trade Names
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	2 years
Minimum [Member] | Reaction Design [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Finite-lived intangible asset, useful life	2 years