Segment Information (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Summary of financial information for the Company's segments
Revenues	$ 510,806	$ 424,856	$ 924,787	$ 789,367
Cost of services (exclusive of items shown separately below)	271,370	229,916	505,215	428,968
Depreciation, depletion, amortization and accretion	63,314	54,299	122,677	105,347
General and administrative expenses	95,881	92,529	182,760	163,253
Gain on sale of businesses	5,884		8,558
Income from operations	86,125	48,112	122,693	91,799
Interest income (expense), net	(16,453)	(12,680)	(28,825)	(26,718)
Earnings from equity-method investments, net	5,499	2,170	5,526	6,155
Income (loss) before income taxes	75,171	37,602	99,394	71,236
Identifiable Assets
Identifiable Assets, Total	3,361,637		3,361,637		2,907,533
Subsea And Well Enhancement [Member]
Summary of financial information for the Company's segments
Revenues	336,037	284,352	598,082	517,118
Cost of services (exclusive of items shown separately below)	194,307	167,875	364,975	310,744
Depreciation, depletion, amortization and accretion	28,056	23,670	53,797	44,092
General and administrative expenses	62,810	59,925	117,467	105,703
Income from operations	50,864	32,882	61,843	56,759
Interest income (expense), net	1,126		2,235
Income (loss) before income taxes	51,990	32,882	64,078	56,759
Identifiable Assets
Identifiable Assets, Total	2,029,481		2,029,481		1,769,813
Drilling Products and Services [Member]
Summary of financial information for the Company's segments
Revenues	149,167	121,337	277,437	235,614
Cost of services (exclusive of items shown separately below)	56,627	43,759	103,324	83,854
Depreciation, depletion, amortization and accretion	32,447	28,053	63,007	56,289
General and administrative expenses	30,431	29,191	59,740	51,190
Income from operations	29,662	20,334	51,366	44,281
Income (loss) before income taxes	29,662	20,334	51,366	44,281
Identifiable Assets
Identifiable Assets, Total	1,002,083		1,002,083		802,785
Marine [Member]
Summary of financial information for the Company's segments
Revenues	25,062	19,167	49,268	36,635
Cost of services (exclusive of items shown separately below)	20,436	18,282	36,916	34,370
Depreciation, depletion, amortization and accretion	2,811	2,576	5,873	4,966
General and administrative expenses	2,640	3,413	5,553	6,360
Gain on sale of businesses	5,884		8,558
Income from operations	5,599	(5,104)	9,484	(9,061)
Income (loss) before income taxes	5,599	(5,104)	9,484	(9,061)
Identifiable Assets
Identifiable Assets, Total	239,100		239,100		255,883
Unallocated [Member]
Summary of financial information for the Company's segments
Interest income (expense), net	(17,579)	(12,680)	(31,060)	(26,718)
Earnings from equity-method investments, net	5,499	2,170	5,526	6,155
Income (loss) before income taxes	(12,080)	(10,510)	(25,534)	(20,563)
Identifiable Assets
Identifiable Assets, Total	$ 90,973		$ 90,973		$ 79,052