Taxation - Earnings before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income Taxes [Line Items]
Domestic (Bermuda)	$ (5,939)	$ (6,519)	$ 11,841	$ (22,970)
Foreign	76,131	33,003	130,255	71,134
Total	$ 70,192	$ 26,484	$ 142,096	$ 48,164

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Subparagraph 1(i)

-Article 4

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration