Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed Estimated Useful Lives (Detail) - SpaceClaim Corporation [Member]	9 Months Ended
	Sep. 30, 2015
Developed Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	10 years
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	6 years
Trade Names
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	6 years
Contract Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	6 years
Non-Compete Agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	2 years