Summary of Significant Accounting Policies Recently Adopted Accounting Standards (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 01, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Oct. 01, 2019	Sep. 30, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts Receivable, Net, Current		$ 313,599		$ 313,599			$ 347,873
Prepaid expenses and other current assets		193,795		193,795			94,814
Other assets		241,271		241,271			141,761
Deferred Revenue, Current		310,586		310,586			330,689
Deferred revenue, net of current portion		410,897		410,897			434,316
Deferred tax liabilities		45,456		45,456			49,931
Other liabilities		97,858		97,858			93,593
Hosting and professional services		260,902	$ 253,610	771,601	$ 785,038
Product and licensing		121,809	132,762	377,349	387,956
Maintenance and support		66,486	63,077	203,484	189,872
Revenues		449,197	449,449	1,352,434	1,362,866
Hosting Cost		154,397	165,578	471,204	517,362
Product and licensing		19,207	13,969	61,897	41,867
Cost of Sales, Maintenance and Support		8,192	9,612	24,919	28,616
Amortization of intangible assets		8,895	12,172	27,700	38,744
Cost of Goods and Services Sold		190,691	201,331	585,720	626,589
Sales and marketing		72,229	77,820	223,343	233,237
Provision (benefit) for income taxes		7,786	$ 9,559	7,814	$ (67,417)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 233,000
Accumulated deficit		(401,741)		(401,741)			$ (740,837)
Deferred Revenue [Domain]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	70,000
Other Assets [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	180,000
Accounts Receivable [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	30,000			26,611
Deferred Project Costs [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	30,000
Deferred Tax Asset [Domain]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 20,000			10,026
Prepaid Expenses and Other Current Assets [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				(65,621)
Other Assets [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				(121,462)
Deferred revenue, current [Domain]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				36,191
Deferred Revenue [Domain]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				19,882
Other Noncurrent Liabilities [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				(11,252)
Retained Earnings [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				(195,117)
ASC 605
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts Receivable, Net, Current		340,210		340,210
Prepaid expenses and other current assets		128,174		128,174
Other assets		119,809		119,809
Deferred Revenue, Current		346,777		346,777
Deferred revenue, net of current portion		430,779		430,779
Deferred tax liabilities		35,430		35,430
Other liabilities		86,606		86,606
Hosting and professional services		268,845		800,780
Product and licensing		127,388		386,851
Maintenance and support		62,099		183,338
Revenues		458,332		1,370,969
Hosting Cost		160,952		474,506
Product and licensing		17,711		48,956
Cost of Sales, Maintenance and Support		8,407		25,181
Cost of Goods and Services Sold		195,965		576,343
Sales and marketing		73,832		224,366
Provision (benefit) for income taxes		7,136		17,843
Accumulated deficit		(596,858)		(596,858)
Cost of professional services and hosting
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		7,943		29,179
Cost of product and licensing
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		5,579		9,502
Cost of maintenance and support
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		(4,387)		(20,146)
Sales Revenue, Net [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		9,135		18,535
Cost, professional services and hosting [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		6,555		3,302
Cost, product and licensing [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		(1,496)		(12,941)
Cost, maintenance and support [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		215		262
Cost, amortization [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		0		0
Cost of Sales [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		5,274		(9,377)
Sales and marketing
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		1,603		1,023
Provision (benefit) for income taxes [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ (650)		$ 10,029
Minimum | Scenario, Forecast [Member] | Deferred Revenue [Domain]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets						$ 130,000
Minimum | Scenario, Forecast [Member] | Assets [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets						110,000
Maximum | Scenario, Forecast [Member] | Deferred Revenue [Domain]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets						175,000
Maximum | Scenario, Forecast [Member] | Assets [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets						$ 145,000