Business Combinations Allocation of Purchase Price and Estimated Useful Life (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Sep. 30, 2019
Identifiable intangible assets:
Goodwill	$ 1,065,379	$ 1,065,379
F5 Networks Acquisition of Nginx
Acquired Finite-Lived Intangible Assets [Line Items]
Net tangible assets	44,494
Identifiable intangible assets:
Identifiable intangible assets amounts	$ 89,300
Identifiable intangible assets useful life	8 years 1 month 6 days
Goodwill	$ 509,414
Total purchase price	643,208
F5 Networks Acquisition of Nginx | Developed Technology Rights
Identifiable intangible assets:
Identifiable intangible assets amounts	$ 62,500
Identifiable intangible assets useful life	7 years
F5 Networks Acquisition of Nginx | Customer Relationships
Identifiable intangible assets:
Identifiable intangible assets amounts	$ 12,000
Identifiable intangible assets useful life	15 years
F5 Networks Acquisition of Nginx | Trade Names
Identifiable intangible assets:
Identifiable intangible assets amounts	$ 14,500
Identifiable intangible assets useful life	7 years
F5 Networks Acquisition of Nginx | Non-competition Agreements
Identifiable intangible assets:
Identifiable intangible assets amounts	$ 300
Identifiable intangible assets useful life	2 years