Annual report pursuant to Section 13 and 15(d)

Revenue Narrative (Details)

v3.19.1
Revenue Narrative (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Jan. 01, 2018
Dec. 31, 2017
Revenue from Contract with Customer [Abstract]      
Contract assets $ 485,000 $ 550,000 $ 0
Contract with customer, liability 11,300,000 $ 8,600,000  
Contract with customer, revenue recognized $ 8,200,000    
Performance obligation, description of timing 30 to 60 days    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Remaining performance obligation $ 12,800,000    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Remaining performance obligation $ 21,600,000