Acquisition - Additional Information (Detail) - USD ($) $ in Thousands				12 Months Ended
	Apr. 30, 2014	Jan. 03, 2014	Apr. 03, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill				$ 1,332,348	$ 1,312,182	$ 1,255,704
Contingent consideration				1,376	2,621
Contingent consideration, installment payments				1,173	4,504	$ 3,174
2015 Other Acquisitions [Member]
Business Acquisition [Line Items]
Total consideration transferred at fair value				49,700
Finite-lived intangibles				24,500
Goodwill				27,500
Business combination, historical carrying value of acquired deferred revenue				900
Acquired deferred revenue, impact on reported revenue				826
Acquired deferred revenue, expected impact on reported revenue in next fiscal year				102
SpaceClaim Corporation [Member]
Business Acquisition [Line Items]
Total consideration transferred at fair value	$ 84,960
Goodwill				48,453
Business combination, historical carrying value of acquired deferred revenue	3,300
Acquired deferred revenue, impact on reported revenue				635	2,000
Goodwill, period increase (decrease)				(4,800)
Deferred revenue				(700)
Cash payments for acquisitions	$ 84,892
Reaction Design [Member]
Business Acquisition [Line Items]
Total consideration transferred at fair value		$ 19,100
Finite-lived intangibles				7,000
Goodwill				9,200
Business combination, historical carrying value of acquired deferred revenue		$ 2,300
Acquired deferred revenue, impact on reported revenue				264	$ 2,000
Goodwill, period increase (decrease)				1,900
Noncontrolling interest, period decrease				(600)
EVEN-Evolutionary Engineering Aktiengesellschaft [Member]
Business Acquisition [Line Items]
Total consideration transferred at fair value			$ 8,100
Finite-lived intangibles				$ 2,600
Finite-lived intangible asset, useful life				5 years
Goodwill				$ 5,900
Cash payments for acquisitions			4,500
Contingent consideration			$ 3,597
Contingent consideration, installment payments				$ 3,000
Minimum [Member] | 2015 Other Acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life				5 years
Minimum [Member] | Reaction Design [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life				2 years
Maximum [Member] | 2015 Other Acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life				10 years
Maximum [Member] | Reaction Design [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset, useful life				11 years