Business Combinations - Estimated Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Goodwill	$ 35,669	$ 32,636
A2iA
Business Acquisition [Line Items]
Current assets			$ 3,929
Property, plant, and equipment			307
Intangible assets			28,610
Goodwill			24,991
Other non-current assets			1,177
Current liabilities			(2,688)
Deferred income tax liabilities			(7,503)
Other non-current liabilities			(7)
Net assets acquired			48,816
ICAR
Business Acquisition [Line Items]
Current assets			2,036
Property, plant, and equipment			83
Intangible assets			6,407
Goodwill			6,936
Other non-current assets			87
Current liabilities			(1,652)
Deferred income tax liabilities			(1,602)
Other non-current liabilities			(828)
Net assets acquired			11,467
Total
Business Acquisition [Line Items]
Current assets			5,965
Property, plant, and equipment			390
Intangible assets			35,017
Goodwill			31,927
Other non-current assets			1,264
Current liabilities			(4,340)
Deferred income tax liabilities			(9,105)
Other non-current liabilities			(835)
Net assets acquired			$ 60,283