Business Segments (Reconciliation of Segment Results to Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Segments [Abstract]
Income (loss) from construction operations	$ 47,943	$ 47,306	$ (270,861)	$ 101,196
Other income, net	1,674	1,909	2,996	3,739
Interest expense	(17,305)	(16,411)	(51,252)	(47,474)
INCOME (LOSS) BEFORE INCOME TAXES	$ 32,312	$ 32,804	$ (319,117)	$ 57,461