Summary of Significant Accounting Policies - Finite-lived Intangible Assets (Details)	12 Months Ended
	Sep. 30, 2017
Minimum | Patents
Finite-Lived Intangible Assets [Line Items]
Amortizable lives	7 years
Minimum | Completed Technology
Finite-Lived Intangible Assets [Line Items]
Amortizable lives	3 years
Minimum | Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Amortizable lives	3 years
Maximum | Patents
Finite-Lived Intangible Assets [Line Items]
Amortizable lives	15 years
Maximum | Completed Technology
Finite-Lived Intangible Assets [Line Items]
Amortizable lives	10 years
Maximum | Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Amortizable lives	11 years