Fair Value Measurement - Additional Information (Detail)	Sep. 30, 2013
Fair Value Measurements [Line Items]
Short-term investment time deposits maturity minimum, in months	3 months
Short-term investment time deposits maturity maximum, in years	1 year

Short term investment time deposits maturity minimum, in months.

No definition available.

Name:	anss_ShortTermInvestmentTimeDepositsMaturityMinimum
Namespace Prefix:	anss_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant