Stock-Based Compensation (Included in Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Document Period End Date			Mar. 31, 2019
Stock based compensation	$ 29,871	$ 31,742	$ 64,211	$ 67,967
Cost of hosting and professional services
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation	5,481	6,306	12,813	13,684
Cost of product and licensing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation	132	112	396	378
Cost of maintenance and support
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation	381	538	147	1,219
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation	7,820	7,757	16,650	16,764
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation	7,638	7,372	16,895	17,536
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation	$ 8,419	$ 9,657	$ 17,310	$ 18,386