Number of shares of equity interests issued or issuable to acquire entity.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

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Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Acquisitions - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands				12 Months Ended
	Nov. 01, 2019	Feb. 01, 2019	May 02, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total consideration transferred at fair value				$ 1,122,764,000
Fair value of common stock issued as consideration in connection with acquisitions				307,173,000	$ 0	$ 0
Acquisition costs				6,600,000
Uncertain tax positions				34,296,000
Livermore Software Technology Corporation
Percentage of shares acquired	100.00%
Total consideration transferred at fair value	$ 777,796,000
Payments to acquire businesses, gross	$ 470,600,000
Business acquisition, equity interest issued or Issuable, number of shares	1,400
Business acquisition, share price	$ 220.74
Fair value of common stock issued as consideration in connection with acquisitions	$ 307,173,000
Uncertain tax positions	$ 34,039,000
Granta Design
Percentage of shares acquired		100.00%
Total consideration transferred at fair value		$ 208,736,000
Payments to acquire businesses, gross		208,700,000
Uncertain tax positions		$ 0
OPTIS
Percentage of shares acquired			100.00%
Total consideration transferred at fair value			$ 290,983,000
Payments to acquire businesses, gross			$ 291,000,000.0
Goodwill, period increase (decrease)				2,600,000
Series of Individually Immaterial Business Acquisitions
Total consideration transferred at fair value				136,232,000
Payments to acquire businesses, gross				136,200,000		$ 67,000,000.0
Uncertain tax positions				$ 257,000