Construction Contracts - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Contractors [Abstract]
Deferred precontract costs	$ 900	$ 1,400
Amortization of pre-contract costs	600	100
Construction receivables retentions	9,000	8,500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Retention payable	5,306	3,037	$ 3,591
Construction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Retention payable	$ 18,000	$ 21,600