Quarterly report pursuant to Section 13 or 15(d)

Revenue from Contracts with Customers - Summary of Accounts And Notes Receivable And Contract Assets and Liabilities (Details)

v3.8.0.1
Revenue from Contracts with Customers - Summary of Accounts And Notes Receivable And Contract Assets and Liabilities (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Revenue from Contract with Customer [Abstract]      
Contract Assets - current   $ 915 $ 973
Contract Assets - noncurrent   0 0
Total contract assets $ 973 915 973
Contract Liabilities - current   (200) (641)
Contract Liabilities - noncurrent   (354) (380)
Total contract liabilities (1,021) $ (554) $ (1,021)
Change in Contract with Customer, Asset [Roll Forward]      
Contract Assets 973    
Decrease due to recognition of revenue that was included in the beginning contract liability balance (424)    
Increase due to cash received, excluding amounts recognized as revenue during the period 0    
Increase due to revenue recognized during the period but contingent on future performance 366    
Contract Assets 915    
Change in Contract with Customer, Liability [Roll Forward]      
Contract Liabilities (1,021)    
Decrease due to recognition of revenue that was included in the beginning contract liability balance 467    
Increase due to cash received, excluding amounts recognized as revenue during the period 0    
Increase due to revenue recognized during the period but contingent on future performance 0    
Contract Liabilities $ (554)