Segments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information
General contracting and real estate services revenues	$ 18,408	$ 57,398	$ 53,971	$ 104,666
General contracting and real estate services | General contracting and real estate services
Segment Reporting Information
General contracting and real estate services revenues	18,408	57,398	53,971	104,666
General contracting and real estate services expenses	18,131	55,342	52,406	100,892
General contracting and real estate services | General contracting and real estate services | Intercompany Eliminations
Segment Reporting Information
General contracting and real estate services revenues	5,400	8,400	7,400	21,500
General contracting and real estate services expenses	$ 5,400	$ 8,300	$ 7,400	$ 21,300