Quarterly report pursuant to Section 13 or 15(d)

Revenue from Contracts with Customers - Additional Information (Details)

v3.19.1
Revenue from Contracts with Customers - Additional Information (Details) - USD ($)
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Contract with customer, liability, noncurrent $ 6,129,000  
Contract with customer, asset, reclassified to receivable 90,344,000 $ 120,072,000
Contract with customer, asset, revenue recognized 90,895,000 87,440,000
Contract with customer, liability, revenue recognized 24,095,000 17,843,000
Contract with customer, liability, billings 18,929,000 16,678,000
Revenue, remaining performance obligation $ 1,674,600,000  
Revenue, remaining performance obligation, percentage 27.00%  
Capitalized contract cost, project development costs $ 2,777,000 2,440,000
Capitalized contract cost, impairment loss $ 0 $ 0
Minimum    
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Contract receivable retainage percentage 5.00%  
Maximum    
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]    
Contract receivable retainage percentage 10.00%