Employee Benefit Plans (Restricted Stock Units) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended							0 Months Ended
	Jan. 31, 2009 Restricted Stock Units (RSUs) [Member]	Oct. 31, 2011 Restricted Stock Units (RSUs) [Member] years		Oct. 31, 2010 Restricted Stock Units (RSUs) [Member] years		Oct. 31, 2009 Restricted Stock Units (RSUs) [Member] years		Oct. 31, 2008 Restricted Stock Units (RSUs) [Member] years	Mar. 24, 2011 2006 Employee Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Units, Beginning balance	2,676	3,730		3,133		2,676
Restricted Stock Units, Granted		1,483		1,228		1,311
Restricted Stock Units, Assumed				713	[1]
Restricted Stock Units, Vested		(1,522)	[2],[3]	(1,221)	[2],[3]	(787)	[2],[3]
Restricted Stock Units, Forfeited		(237)		(123)		(67)
Restricted Stock Units, Ending balance		3,454		3,730		3,133		2,676
Weighted Average Grant Date Fair Value, Beginning balance	$ 25.45	$ 22.71		$ 22.63		$ 25.45
Weighted Average Grant Date Fair Value, Granted		$ 26.89		$ 22.00		$ 18.78
Weighted Average Grant Date Fair Value, Assumed				$ 23.69	[1]
Weighted Average Grant Date Fair Value, Vested		$ 23.11	[2],[3]	$ 22.40	[2],[3]	$ 25.64	[2],[3]
Weighted Average Grant Date Fair Value, Forfeited		$ 23.49		$ 22.51		$ 24.64
Weighted Average Grant Date Fair Value		$ 24.28		$ 22.71		$ 22.63		$ 25.45
Weighted Average Remaining Contractual Life (In Years)		1.48		1.41		1.41		1.61
Aggregate Fair Value, Vested		$ 35,164	[2],[3]	$ 27,345	[2],[3]	$ 14,859	[2],[3]
Share reserve ratio	1.36								2.18
Revised share reserve ratio									1.25
Vesting period, minimum (in years)		three
Vesting period, maximum (in years)		four

[1] The Company assumed restricted stock units outstanding under various plans through acquisitions.

[2] Represents the market value of Synopsys common stock on the date the restricted stock unit vests.

[3] The number of vested restricted stock units includes shares that were withheld on behalf of employees to satisfy the statutory tax withholding requirements.