Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)

v3.19.2
Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)
 6 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
Segment
Dec. 31, 2018
USD ($)
Jan. 01, 2019
USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Standard warranty period offered 3 years    
Cash payments received in advance of satisfying performance obligations $ 5,018,000    
Performance obligation partially offset of revenue recognized 3,055,000    
Deferred capped rental revenue $ 0 $ 0  
Rental revenue earned 30 days    
Operating lease right-of-use asset $ 5,461,000   $ 6,418,000
Operating lease liabilities $ 2,006,000    
Number of operating segments | Segment 1    
Number of reportable segments | Segment 1    
ASU 2016-02      
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Operating lease right-of-use asset $ 6,400,000    
Operating lease liabilities 6,400,000    
Cumulative effect adjustment on retained earnings 0    
Lifetime Warranties | Direct-to-Consumer      
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Sales revenue $ 16,837,000 $ 14,874,000