Construction Contracts - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contractors [Abstract]
Deferred precontract costs	$ 1,700	$ 900
Amortization of pre-contract costs	800	600
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Construction payables	6,088	5,306	$ 3,037
Construction receivables retentions	17,100	9,000
Construction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Construction payables	$ 17,700	$ 18,000