Quarterly report pursuant to Section 13 or 15(d)

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

v3.21.2
Organization and Summary of Significant Accounting Policies - Additional Information (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
segment
Jun. 30, 2020
USD ($)
Jul. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Significant Accounting Policies [Line Items]            
Number of operating segments | segment     2      
Number of corporate non-operating segments | segment     1      
Short-term investments $ 0   $ 0      
Prepaid contract costs 0   0     $ 0
Federal income tax expense (benefit) 0 $ 0 $ 0 $ 0    
Other (income) expense, net            
Significant Accounting Policies [Line Items]            
Gain on settlement of contract dispute for project completed in 2015       $ 10,000,000.0    
Minimum            
Significant Accounting Policies [Line Items]            
Property, plant and equipment, useful life     3 years      
Maximum            
Significant Accounting Policies [Line Items]            
Property, plant and equipment, useful life     25 years      
LC Facility            
Significant Accounting Policies [Line Items]            
Restricted cash 10,000,000.0   $ 10,000,000.0     $ 0
Outstanding letters of credit $ 10,000,000.0   $ 10,000,000.0   $ 7,000,000.0  
LC Facility | Balance Sheet Date Classified as Current            
Significant Accounting Policies [Line Items]            
Maturity date, description     maturity dates of twelve months or less from the balance sheet date classified as current      
LC Facility | Balance Sheet Date Classified as Noncurrent            
Significant Accounting Policies [Line Items]            
Maturity date, description     maturity dates of longer than twelve months from the balance sheet date classified as noncurrent