Goodwill and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Nov. 30, 2018	Sep. 30, 2018
Goodwill And Other Intangible Assets [Line Items]
Goodwill	$ 5,980		$ 4,343
Other intangible assets, net	12,163		8,006
Optoseis Technology
Goodwill And Other Intangible Assets [Line Items]
Goodwill	5,980	$ 1,600	4,343
Total other intangible assets	12,719	$ 4,500	8,200
Accumulated amortization	(556)		(194)
Other intangible assets, net	$ 12,163		8,006
Weighted-Average Remaining Useful Lives (in years)	10 years 10 months 24 days
Optoseis Technology | Developed Technology
Goodwill And Other Intangible Assets [Line Items]
Total other intangible assets	$ 6,419		4,200
Weighted-Average Remaining Useful Lives (in years)	17 years 8 months 12 days
Optoseis Technology | Customer Relationships
Goodwill And Other Intangible Assets [Line Items]
Total other intangible assets	$ 4,200		2,500
Weighted-Average Remaining Useful Lives (in years)	3 years 8 months 12 days
Optoseis Technology | Trade Names
Goodwill And Other Intangible Assets [Line Items]
Total other intangible assets	$ 1,930		1,400
Weighted-Average Remaining Useful Lives (in years)	4 years 8 months 12 days
Optoseis Technology | Non-compete Agreements
Goodwill And Other Intangible Assets [Line Items]
Total other intangible assets	$ 170		$ 100
Weighted-Average Remaining Useful Lives (in years)	3 years 8 months 12 days