Revenue from Contracts with Customers - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Amount of revenue recognized from beginning deferred revenue and backlog	$ 244.6	$ 209.3

Contract with Customer, Liability, Revenue Recognized, Backlog Included

No definition available.

Name:	anss_ContractWithCustomerLiabilityRevenueRecognizedBacklogIncluded
Namespace Prefix:	anss_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration