Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Schedule of Allowances for Accounts Receivable (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Schedule of Allowances for Accounts Receivable (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Allowances - accounts receivable    
Doubtful accounts $ 1,415 $ 1,869
Rental revenue adjustments 947 6,078
Sales returns 904 585
Total allowances - accounts receivable $ 3,266 $ 8,532
Doubtful accounts, percentage 4.10% 4.70%
Rental revenue adjustments, percentage 2.70% 15.40%
Sales returns, percentage 2.60% 1.50%
Total allowances - accounts receivable, percentage 9.40% 21.60%