Legal Matters (Details) (USD $)	1 Months Ended	12 Months Ended				1 Months Ended			1 Months Ended				1 Months Ended
	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Oct. 31, 2009	Mar. 31, 2011 WesternGeco [Member] mi	Jun. 30, 2009 WesternGeco [Member] Patent	Dec. 31, 2012 WesternGeco [Member]	Aug. 16, 2012 WesternGeco [Member] Pending Litigation [Member]	Aug. 16, 2012 WesternGeco [Member] Pending Litigation [Member] Lost Profits [Member]	Aug. 16, 2012 WesternGeco [Member] Pending Litigation [Member] Lost Royalties [Member]	May 31, 2012 Fletcher [Member]	Apr. 30, 2012 Sercel [Member]	Feb. 28, 2011 Sercel [Member]	Sep. 30, 2010 Sercel [Member]	Jan. 31, 2010 Sercel [Member]
Legal Matters (Textual) [Abstract]
Number of patent apparatus claims contained							4
Minimum distance from coast to make alleged activities not actionable under patent infringement law						12
Total damages awarded									$ 105,900,000	$ 93,400,000	$ 12,500,000
Probable estimated loss contingency								10,000,000
Accrued legal contingency	10,000,000	10,000,000	0
Principal amount of promissory note												35,000,000
Compensatory damages awarded in connection with infringement of patent																25,200,000
Disallowed the award of lost profits associated with infringing products															5,400,000
Disallowed the award of lost profits associated with certain infringing pre-verdict marine sales															9,000,000
Awarded for damages, plus interest														10,700,000
Compensatory damages					21,700,000
Amount paid in full satisfaction of the judgment				25,000,000
Gain on legal settlement	$ 19,000,000	$ 20,895,000	$ 0	$ 24,500,000									$ 12,000,000