Business Segment Information (Schedule Of Segment Reporting Information By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Revenues	$ 407,927	$ 291,607
Income (loss) from operations	132,197	52,111
Assets	3,664,943		3,582,347
Equity in earnings of equity investments	407	5,650
Contracting Services [Member]
Revenues	244,544	131,537
Income (loss) from operations	59,124	3,266
Assets	2,128,639		2,006,065
Production Facilities [Member]
Revenues	20,022	15,570
Income (loss) from operations	10,049	5,956
Assets	534,155		534,776
Oil and Gas [Member]
Revenues	178,085	168,859
Income (loss) from operations	76,942	53,240
Assets	1,002,149		1,041,506
Intercompany Elimination [Member]
Revenues	(34,724)	(24,359)
Income (loss) from operations	(3,020)	90
Corporate [Member]
Income (loss) from operations	$ (10,898)	$ (10,441)