Supplementary Financial Information

12 Months Ended

Sep. 30, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Supplementary Financial Information

21.  Supplementary Financial Information

The following is a summary of the activity in our allowance for doubtful accounts (in thousands):

	Years Ended September 30,
	2019			2018			2017
Balance at beginning of year	$	454		$	356		$	1,431
Provision		200			102			117
Write offs		(402	)		(9	)		(1,171	)
Adjustment (1)		(80	)		5			(21	)
Balance at end of year	$	172		$	454		$	356

(1) Primarily foreign currency translation adjustments.