Construction Contracts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Capitalized contract cost, amortization	$ 200	$ 100
Construction receivables retentions	10,900		$ 9,000
Retention payable	6,311	$ 3,622	5,306	$ 3,037
Construction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Retention payable	16,000		18,000
Portion Attributable To Pending Contracts
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred pre-contract costs	$ 1,500		$ 900