Business Segment Information (Schedule Of Segment Reporting Information By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues	$ 347,394	$ 338,319	$ 755,321	$ 629,926
Income (loss) from operations	78,487	76,418	210,684	128,529
Equity in earnings of equity investments	5,748	5,887	6,155	11,537
Contracting Services [Member]
Revenues	209,557	171,353	454,101	302,890
Income (loss) from operations	19,223	30,565	78,347	33,831
Production Facilities [Member]
Revenues	19,963	20,545	39,985	36,115
Income (loss) from operations	9,882	11,920	19,931	17,876
Oil and Gas [Member]
Revenues	149,933	172,458	328,018	341,317
Income (loss) from operations	60,442	43,064	137,384	96,304
Intercompany Elimination [Member]
Revenues	(32,059)	(26,037)	(66,783)	(50,396)
Income (loss) from operations	98	(19)	(2,922)	71
Corporate [Member]
Income (loss) from operations	$ (11,158)	$ (9,112)	$ (22,056)	$ (19,553)