Revenue Recognition (Tables)
 3 Months Ended
Mar. 31, 2019
Revenue Recognition  
Schedule of revenue from United States, Canada and all other international dealers and distributors combined

The following table sets forth revenue from the United States, Canada and all other international dealers and distributors combined (in thousands):

 

 

 

 

 

 

 

 

 

 

 

 

Three Months Ended

 

 

 

 

March 31,

 

 

 

    

2019

    

2018

    

 

Revenue-United States

 

$

41,003

 

$

40,964

 

 

Revenue-Canada

 

 

5,171

 

 

5,264

 

 

Revenue-all other international sources

 

 

14,251

 

 

12,921

 

 

Total revenue

 

$

60,425

 

$

59,149

 

 

International revenue (excluding Canada) as a percent of total revenue

 

 
24

%  

 
22

%  

 

 

Summary of changes in the allowance for doubtful accounts

The following table presents the changes in the allowance for doubtful accounts (in thousands):

 

 

 

 

 

 

    

Allowance

 

Balance at December 31, 2018

 

$

1,529

 

Provision

 

 

 8

 

Write-offs

 

 

(291)

 

Balance at March 31, 2019

 

$

1,246

 

 

Schedule of changes in deferred revenue

The following table presents the changes in deferred revenue for the three months ended March 31, 2019 (in thousands):

 

 

 

 

 

    

Deferred Revenue

Balance at December 31, 2018

 

$

8,699

Deferred revenue

 

 

4,593

Recognition of deferred revenue

 

 

(4,548)

Balance at March 31, 2019

 

$

8,744