Quarterly Financial Information (Summary Of Consolidated Quarterly Financial Information) (Details) (USD $)	3 Months Ended																		12 Months Ended				3 Months Ended			6 Months Ended	12 Months Ended			3 Months Ended
	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2010		Sep. 30, 2010		Jun. 30, 2010		Mar. 31, 2010		Sep. 30, 2009	Jun. 30, 2009	Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009	Dec. 31, 2011 Reserve Impairment [Member]	Dec. 31, 2011 Australian Well Invention Equipment [Member]	Dec. 31, 2011 United Kingdom [Member]	Jun. 30, 2010 United Kingdom [Member]	Dec. 31, 2011 United Kingdom [Member]	Dec. 31, 2010 United Kingdom [Member]	Dec. 31, 2009 United Kingdom [Member]	Dec. 31, 2011 Sapura [Member]
Quarterly Financial Information [Line Items]
Net revenues	$ 396,185,000		$ 372,496,000		$ 338,319,000		$ 291,607,000		$ 306,337,000		$ 392,669,000		$ 299,262,000		$ 201,570,000				$ 1,398,607,000	$ 1,199,838,000		$ 1,461,687,000					$ 275,499,000	$ 198,011,000	$ 124,896,000
Gross profit	31,023,000	[1]	122,295,000	[1]	100,198,000	[1]	77,076,000	[1]	16,082,000	[2]	86,552,000	[2]	(94,818,000)	[2]	25,856,000	[2]			330,592,000	33,672,000		243,162,000
Net income	16,763,000	[3]	46,026,000	[3]	41,323,000	[3]	25,867,000	[3]	(49,811,000)	[4]	26,171,000	[4]	(85,517,000)	[4]	(17,831,000)	[4]			129,979,000	(126,988,000)		156,054,000
Net income applicable to common shareholders	16,753,000		46,016,000		41,313,000		25,857,000		(49,821,000)		26,161,000		(85,551,000)		(17,891,000)				129,939,000	(127,102,000)		101,867,000
Basic earnings per common share	$ 0.16		$ 0.43		$ 0.39		$ 0.24		$ (0.48)		$ 0.25		$ (0.82)		$ (0.17)				$ 1.23	$ (1.22)		$ 1.01
Diluted earnings per common share	$ 0.16		$ 0.43		$ 0.39		$ 0.24		$ (0.48)		$ 0.25		$ (0.82)		$ (0.17)				$ 1.22	$ (1.22)		$ 0.96
Goodwill impairments									16,700,000											16,743,000	[5]
Oil and gas impairments	107,500,000		2,400,000		22,700,000		0		9,200,000		900,000		159,900,000		11,100,000		64,600,000	48,200,000	132,603,000	181,083,000		120,550,000	79,300,000			5,000,000	20,000,000	5,000,000
Impairment of long-lived assets held-for-use																								6,600,000
Other than temporary impairment non-cash									2,200,000										10,563,000	2,240,000										10,600,000
Increase in expected asset retirement cost	28,200,000																		20,000,000						15,900,000
Tax benefit related to reorganization																								$ 31,300,000

[1] Includes oil and gas property impairment charges totaling $22.7 million in the second quarter of 2011 and $2.4 million in the third quarter of 2011. Our fourth quarter of 2011 includes a total of $107.5 million of impairment charges, including $79.3 million related to eight oil and gas properties to reduce them to their estimated fair value at December 31, 2011 and $28.2 million to increase certain non-producing properties estimated asset retirement obligations, including $15.9 million related to our one U.K. oil and gas property (Note 5). The fourth quarter also includes a $6.6 million impairment charge to reduce our Australian well intervention equipment to is estimated fair value at December 31, 2011. There were no asset impairment charges in the first quarter of 2011.

[2] Includes oil and gas property impairment charges totaled $11.1 in the first quarter of 2010, $159.9 million in the second quarter of 2010, $0.9 million in the third quarter of 2010 and $9.2 million in the fourth quarter of 2010.

[3] Our fourth quarter 2011 includes a $10.6 million other than temporary impairment loss on our equity investment in our Australian joint venture (Note 7). The fourth quarter also includes a $31.3 million tax benefit related to reorganization of our Australian well intervention business.

[4] Includes an impairment charges of $16.7 million to reduce goodwill associated with our Australia well intervention business in the fourth quarter of 2010 (Note 2).

[5] Amount reflects full write off of goodwill associated with our WOSEA operations.