XML 36 R23.htm IDEA: XBRL DOCUMENT v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]  
Schedule of allowance for doubtful accounts
The following table presents the changes in the allowance for doubtful accounts as of December 31, 2018, 2017 and 2016 (in thousands):
 
2018
 
2017
 
2016
Allowance for doubtful accounts, beginning balance
$
1,577

 
$
2,473

 
$
2,057

Provision for doubtful accounts
4,940

 
2,646

 
3,693

Amounts written off
(3,685
)
 
(3,542
)
 
(3,277
)
Allowance for doubtful accounts, ending balance
$
2,832

 
$
1,577

 
$
2,473