Construction Contract and Other Service Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Remaining performance obligations	$ 74,100
Remaining performance obligation expected to be recognized during the remainder of year	26,000
Construction Contract Revenue
Disaggregation of Revenue [Line Items]
Performance obligations satisfied or already satisfied		$ 32
Deferred incremental costs incurred	$ 0	$ 0