PENSIONS - Employer Contributions and Payments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
UK Scheme
Pensions:
Estimated future employer contributions in next fiscal year	$ 617
Estimated future benefit payments:
2012	231
2013	231
2014	231
2015	231
2016	231
2017 - 2021	2,079
Marine Scheme
Pensions:
Estimated future employer contributions in next fiscal year	1,800
Estimated future benefit payments:
2012	3,000
2013	3,000
2014	3,000
2015	3,000
2016	3,000
2017 - 2021	$ 15,000

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph g

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsInNextFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant