Segments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information
General contracting and real estate services revenues	$ 56,671	$ 33,200	$ 120,190	$ 70,003
General contracting and real estate services expenses	54,015	32,025	115,211	67,062
Non-cash stock compensation			832	652
General and Administrative Expense
Segment Reporting Information
Non-cash stock compensation	200	200	600	500
General contracting and real estate services | Maximum
Segment Reporting Information
Non-cash stock compensation	100	100	400	300
General contracting and real estate services | Intersegment Eliminations
Segment Reporting Information
General contracting and real estate services revenues	11,600	17,900	17,500	32,900
General contracting and real estate services expenses	$ 11,600	$ 17,800	$ 17,300	$ 32,600