Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 653,345	$ 567,842	$ 1,758,140	$ 1,563,797
Gain (Loss) on Hedging Activity	(4,700)	(200)	(10,700)	3,000
Construction [Member]
Disaggregation of Revenue [Line Items]
Revenues	631,380	554,820	1,695,558	1,518,278
Land [Member]
Disaggregation of Revenue [Line Items]
Revenues	8,511	829	23,042	6,424
Financial Services Sector [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 13,454	$ 12,193	$ 39,540	$ 39,095