v2.4.0.6

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Level 3 Inputs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	$ 452,813	$ 400,386
Total unrealized gains (losses)
Included in net investment income	29,184	23,798
Included in other income (loss)	18,563	40,068
Total realized gains
Included in net investment income	0	0
Included in other income (loss)	(55,308)	10,955
Total foreign exchange losses	353	1,318
Purchases	21,970	19,096
Sales	(13,431)	(4,160)
Settlements	40,376	(19,440)
Net transfers into Level 3	0	0
Balance at end of the period	494,520	472,021
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in net investment income	29,184	23,798
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in other loss	10,513	45,474
Fixed Maturity Investments, Trading [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	27,761	21,785
Total unrealized gains (losses)
Included in net investment income	77	41
Included in other income (loss)	0	0
Total realized gains
Included in net investment income	0	0
Included in other income (loss)	0	0
Total foreign exchange losses	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Net transfers into Level 3	0	0
Balance at end of the period	27,838	21,826
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in net investment income	77	41
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in other loss	0	0
Other Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	396,526	362,102
Total unrealized gains (losses)
Included in net investment income	29,107	23,757
Included in other income (loss)	0	0
Total realized gains
Included in net investment income	0	0
Included in other income (loss)	0	0
Total foreign exchange losses	730	1,369
Purchases	12,689	17,465
Sales	0	0
Settlements	(20,515)	(22,878)
Net transfers into Level 3	0	0
Balance at end of the period	418,537	381,815
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in net investment income	29,107	23,757
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in other loss	0	0
Other Assets and (Liabilities) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	28,526	16,499
Total unrealized gains (losses)
Included in net investment income	0	0
Included in other income (loss)	18,563	40,068
Total realized gains
Included in net investment income	0	0
Included in other income (loss)	(55,308)	10,955
Total foreign exchange losses	(377)	(51)
Purchases	9,281	1,631
Sales	(13,431)	(4,160)
Settlements	60,891	3,438
Net transfers into Level 3	0	0
Balance at end of the period	48,145	68,380
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in net investment income	0	0
Change in unrealized gains (losses) for the period included in earnings for assets held at the end of the period included in other loss	$ 10,513	$ 45,474

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- Definition

This item represents the amount of the total foreign exchange gains or losses for the period which are included in the statement of income in net foreign exchange gains or losses. Such foreign exchange gains or losses relate to those assets or liabilities still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

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- Definition

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- Definition

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- Definition

This item represents the amount of the total realized gains or losses for the period which are included in the statement of income (or changes in net assets) in other income. The fair value of which assets was or is measured on a recurring basis using significant unobservable inputs (Level 3).

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+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph d

-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.



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- Definition

This item represents the amount of the total change in unrealized (holding) gains or losses for the period which are included in the statement of income (or changes in net assets) in other income. Such unrealized (holding) gains or losses relate to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph d

-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 820

-SubTopic 10

-Section 50

-Paragraph 2

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- Definition

Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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Period Type:	duration

X

- Definition

Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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- Definition

Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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- Definition

This element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(3)

-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

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-Name Accounting Standards Codification

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-Section 50

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-Subparagraph (c)(3)

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- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-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 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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