FAIR VALUE MEASUREMENTS (DETAILS 2) (USD $) In Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Corporate Debt [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	$ 1,550	$ 3,100	$ 1,550	$ 18,130
Total net realized and unrealized gains included in net income	0	0	0	0
Total net realized and unrealized losses included in net income	0	0	0	(1,550)
Change in net unrealized gains included in other comprehensive income	0	0	0	3,751
Change in net unrealized losses included in other comprehensive income	0	0	0	(34)
Purchases	0	0	0	0
Sales	0	0	0	(12)
Settlements / distributions	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	(17,185)
Balance at end of period	1,550	3,100	1,550	3,100
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	0	0	0	(1,550)
CMBS [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	0	3,600	0	2,409
Total net realized and unrealized gains included in net income	0	0	0	0
Total net realized and unrealized losses included in net income	0	0	0	(119)
Change in net unrealized gains included in other comprehensive income	0	180	0	1,273
Change in net unrealized losses included in other comprehensive income	0	0	0	(238)
Purchases	0	0	0	3,474
Sales	0	0	0	(206)
Settlements / distributions	0	0	0	(694)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	(3,780)	0	(5,899)
Balance at end of period	0	0	0	0
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	0	0	0	0
Non-Agency RMBS [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	11,268	2,973	19,678	6,639
Total net realized and unrealized gains included in net income	0	0	0	0
Total net realized and unrealized losses included in net income	0	0	0	(581)
Change in net unrealized gains included in other comprehensive income	37	92	124	1,238
Change in net unrealized losses included in other comprehensive income	(40)	(7)	(55)	(27)
Purchases	0	0	0	0
Sales	0	0	0	(211)
Settlements / distributions	(610)	(207)	(1,583)	(692)
Transfers into Level 3	0	0	0	780
Transfers out of Level 3	(1,525)	(2,851)	(9,034)	(7,146)
Balance at end of period	9,130	0	9,130	0
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	0	0	0	0
ABS [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	44,733	46,816	43,178	43,585
Total net realized and unrealized gains included in net income	0	0	0	0
Total net realized and unrealized losses included in net income	0	0	0	(1,134)
Change in net unrealized gains included in other comprehensive income	2,769	0	4,624	2,406
Change in net unrealized losses included in other comprehensive income	(558)	(47)	(858)	(71)
Purchases	0	0	0	4,000
Sales	0	0	0	(2,004)
Settlements / distributions	0	(356)	0	(369)
Transfers into Level 3	1,293	0	1,293	0
Transfers out of Level 3	0	(4,190)	0	(4,190)
Balance at end of period	48,237	42,223	48,237	42,223
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	0	0	0	0
Fixed Maturities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	57,551	56,489	64,406	70,763
Total net realized and unrealized gains included in net income	0	0	0	0
Total net realized and unrealized losses included in net income	0	0	0	(3,384)
Change in net unrealized gains included in other comprehensive income	2,806	272	4,748	8,668
Change in net unrealized losses included in other comprehensive income	(598)	(54)	(913)	(370)
Purchases	0	0	0	7,474
Sales	0	0	0	(2,433)
Settlements / distributions	(610)	(563)	(1,583)	(1,755)
Transfers into Level 3	1,293	0	1,293	780
Transfers out of Level 3	(1,525)	(10,821)	(9,034)	(34,420)
Balance at end of period	58,917	45,323	58,917	45,323
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	0	0	0	(1,550)
Alternative Investments [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	623,650	496,087	519,296	520,188
Total net realized and unrealized gains included in net income	4,758	23,469	47,598	35,818
Total net realized and unrealized losses included in net income	(35,410)	0	(41,709)	0
Change in net unrealized gains included in other comprehensive income	0	0	0	0
Change in net unrealized losses included in other comprehensive income	0	0	0	0
Purchases	60,000	25,000	180,000	45,000
Sales	(729)	(3,588)	(24,923)	(47,992)
Settlements / distributions	(8,999)	(7,896)	(36,992)	(19,942)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance at end of period	643,270	533,072	643,270	533,072
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	(30,376)	23,469	6,732	35,818
Total Assets [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	681,201	552,576	583,702	590,951
Total net realized and unrealized gains included in net income	4,758	23,469	47,598	35,818
Total net realized and unrealized losses included in net income	(35,410)	0	(41,709)	(3,384)
Change in net unrealized gains included in other comprehensive income	2,806	272	4,748	8,668
Change in net unrealized losses included in other comprehensive income	(598)	(54)	(913)	(370)
Purchases	60,000	25,000	180,000	52,474
Sales	(729)	(3,588)	(24,923)	(50,425)
Settlements / distributions	(9,609)	(8,459)	(38,575)	(21,697)
Transfers into Level 3	1,293	0	1,293	780
Transfers out of Level 3	(1,525)	(10,821)	(9,034)	(34,420)
Balance at end of period	702,187	578,395	702,187	578,395
Level 3 gains / (losses) included in earnings attributable to the change in unrealized gains / losses relating to those assets and liabilities held at the reporting date	$ (30,376)	$ 23,469	$ 6,732	$ 34,268

This element represents total gains for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

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- Definition

This element represents total gains for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity).

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This element represents total gains (losses) for the period, pertaining to assets held at the balance sheet date and arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

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- Definition

This element represents total losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

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This element represents total losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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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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.

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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.

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- Definition

Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

+ 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)(3)

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

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- Definition

Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

+ 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)(3)

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

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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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