Valuation and Qualifying Accounts

12 Months Ended

Sep. 30, 2018

Valuation And Qualifying Accounts [Abstract]

Valuation and Qualifying Accounts

Schedule II

Geospace Technologies Corporation and Subsidiaries

Valuation and Qualifying Accounts

(In thousands)

	Balance at Beginning of Period		Charged to Costs and Expenses, net of Recoveries			Charged to Other Assets		(Deductions) and Additions			Balance at End of Period
Year ended September 30, 2018
Allowance for doubtful accounts on accounts and financing    receivables	$	2,415	$	1,009		$	—	$	(122	)	$	3,302
Year ended September 30, 2017
Allowance for doubtful accounts on accounts and financing    receivables	$	2,949	$	(380	)	$	—	$	(154	)	$	2,415
Year ended September 30, 2016
Allowance for doubtful accounts on accounts and financing    receivables	$	2,516	$	763		$	—	$	(330	)	$	2,949
	Balance at Beginning of Period		Charged to Costs and Expenses			Charged to Other Assets		(Deductions) and Additions			Balance at End of Period
Year ended September 30, 2018
Inventory obsolescence reserve	$	29,614	$	4,353		$	—	$	(3,416	)	$	30,551
Year ended September 30, 2017
Inventory obsolescence reserve	$	9,674	$	21,472		$	—	$	(1,532	)	$	29,614
Year ended September 30, 2016
Inventory obsolescence reserve	$	6,675		11,212		$	—	$	(8,213	)	$	9,674