XML 42 R27.htm IDEA: XBRL DOCUMENT v3.10.0.1
Supplementary Financial Information
 12 Months Ended
Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Supplementary Financial Information
Supplementary Financial Information

The following is a summary of the activity in our allowance for doubtful accounts (in thousands):
 
 
Years Ended September 30,
 
2018
 
2017
 
2016
Balance at beginning of year
$
866

 
$
3,730

 
$
5,009

Provision / (Reversal)
45

 
(720
)
 
1,698

Write offs
(33
)
 
(1,249
)
 
(1,942
)
Adjustment (1) (2) (3)
529

 
(895
)
 
(1,035
)
Balance at end of year
$
1,407

 
$
866

 
$
3,730


(1) 2018 amount relates to unbilled accounts receivable that were deemed uncollectible.
(2) 2016 amount primarily relates to partial collection of cancellation fees that were legally owed to us but for which collectability was not assured.
(3) Includes foreign currency translation adjustments.