Income Taxes (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Income Tax Disclosure [Line Items]
Effective income tax rate		(14.00%)	129.00%	18.00%
Income before income taxes		$ 126,234,000	$ 120,736,000	$ 104,548,000
Statutory federal income tax rate		35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Withholding, Amount		6,000,000
Effective Income Tax Rate Reconciliation, Tax Settlement, Foreign, Amount		5,300,000
Intangible assets acquired		133,500,000
Deferred Tax Liabilities, Other Finite-Lived Assets		(40,900,000)
Effect of change in the tax status of the foreign legal entity			4,200,000
Effective income tax rate, one-time increase		0.00%	3.00%	1.00%
Tax benefit related to research and development				2,300,000
Net increase provision for income tax benefit				1,500,000
Tax provision related to research and development cost sharing prepayment		2,000,000	7,800,000	7,500,000	6,000,000
Prepaid income taxes	700,000	11,500,000	700,000
Income taxes payable	16,400,000	14,400,000	16,400,000
Accrued income taxes	800,000	7,100,000	800,000
Other current liabilities	4,400,000	2,100,000	4,400,000
Other liabilities	11,200,000	5,200,000	11,200,000
Income tax payments		35,400,000	53,000,000	28,100,000
Net deferred tax assets	11,283,000	4,400,000	11,283,000
Establish valuation allowance in the U.S. on foreign tax credits	124,500,000	0	124,500,000	0
Net operating loss carryforwards		79,000,000
Valuation allowance	170,404,000	156,547,000	170,404,000	38,600,000	40,500,000
Interest expense		(1,200,000)	300,000	300,000
Penalty expense		0	100,000	100,000
Interest expense related to income tax accruals	2,300,000	1,100,000	2,300,000
Accrued tax penalties	100,000	100,000	100,000
Unrecognized tax benefit	19,100,000	13,700,000	19,100,000	16,200,000	15,900,000
Income tax provision upon recognition of unrecognized tax benefit		12,900,000
Unrecognized tax benefits, increase in valuation allowance upon recognition		7,600,000
Unrecognized tax benefits, increase to additional paid-in capital upon recognition		800,000
Potential decrease in unrecognized tax benefits		2,000,000
Stock-based compensation		48,787,000	51,305,000	45,402,000
Tax benefit recognition related to stock based compensation		2,700,000	3,900,000	15,200,000
Increase (decrease) in income taxes payable		15,211,000	4,005,000	(18,931,000)
Windfall tax deductions not yet recognized		39,300,000
Income tax charge (reversal) on undistributed earnings of foreign subsidiaries				6,500,000
Undistributed earnings of subsidiaries	267,000,000	378,000,000	267,000,000
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	0	5,994,000	0
Domestic Country [Member]
Income Tax Disclosure [Line Items]
Business reorganization taxable gains				46,400,000
Valuation allowance		129,900,000
Intercompany loan receivable from foreign subsidiary		154,400,000
Deferred Tax Assets, Tax Credit Carryforwards, Foreign		6,000,000
Domestic Country [Member] | Research Tax Credit Carryforward [Member]
Income Tax Disclosure [Line Items]
Credit carryforwards		14,700,000
Foreign Country [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		143,900,000
Valuation allowance		26,600,000
Credit carryforwards		6,800,000
Japan [Member]
Income Tax Disclosure [Line Items]
Impact of a Japanese legislative change on our Japan entities' deferred tax assets			1,400,000
Windfall Tax Benefit [Member]
Income Tax Disclosure [Line Items]
Increase (decrease) in income taxes payable		300,000	1,100,000	9,400,000
Windfall tax deductions not yet recognized		23,000,000
Massachusetts Research And Development Member | Research Tax Credit Carryforward [Member]
Income Tax Disclosure [Line Items]
Credit carryforwards		19,400,000
All Acquisitions [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		55,700,000
Servigistics and Enigma [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets, change in valuation allowance		(36,700,000)
Net operating loss carryforwards		41,900,000
Prior Acquisitions [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		13,800,000
Deferred Tax Asset, Pension [Member]
Income Tax Disclosure [Line Items]
Deferred tax assets, change in valuation allowance		$ (7,900,000)