Business Segments (Reconciliation Of Segment Results To Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting [Abstract]
Income from construction operations	$ 52,093	$ 83,021	$ 170,550	$ 187,944
Other income (expense)	(464)	(8,048)	1,142	(8,364)
Interest expense	(16,694)	(25,613)	(52,442)	(58,513)
Income before income taxes	$ 34,935	$ 49,360	$ 119,250	$ 121,067