Quarterly report pursuant to Section 13 or 15(d)

Revenue from Contracts with Customers - Additional Information (Details)

v3.19.3
Revenue from Contracts with Customers - Additional Information (Details) - USD ($)
 3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]          
Contract with customer, liability, noncurrent $ 5,534,000   $ 5,534,000   $ 6,343,000
Contract with customer, asset, reclassified to receivable     351,180,000 $ 398,917,000  
Contract with customer, asset, revenue recognized     321,344,000 344,768,000  
Contract with customer, liability, revenue recognized     58,594,000 116,892,000  
Contract with customer, liability, billings     53,652,000 119,961,000  
Revenue, remaining performance obligation $ 1,696,200,000   $ 1,696,200,000    
Revenue, remaining performance obligation, percentage 29.00%   29.00%    
Capitalized project development costs, noncurrent $ 1,673,000   $ 1,673,000   $ 639,000
Capitalized contract cost, project development costs $ 2,048,000 $ 7,561,000 13,081,000 13,571,000  
Capitalized contract cost, impairment loss     $ 0 $ 0  
Minimum          
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]          
Contract receivable retainage percentage 5.00%   5.00%    
Maximum          
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]          
Contract receivable retainage percentage 10.00%   10.00%