FAIR VALUE MEASUREMENTS (DETAILS 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Fixed Maturities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	$ 34,817	$ 70,931
Transfers into Level 3	10,572	0
Transfers out of Level 3	(6,165)	(1,222)
Included in earnings	0	1,439
Included in OCI	3,636	1,651
Purchases	60,784	0
Sales	0	0
Settlements / distributions	(30,013)	(37,982)
Balance at end of period	73,631	34,817
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
Other Investments [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	557,055	422,431
Transfers into Level 3	12,355	0
Transfers out of Level 3	(32,255)	0
Included in earnings	48,478	86,066
Included in OCI	0	0
Purchases	75,542	142,471
Sales	0	0
Settlements / distributions	(43,331)	(93,913)
Balance at end of period	617,844	557,055
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	48,339	86,066
Other Assets [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	984	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	5,112	2,084
Included in OCI	0	0
Purchases	0	(1,100)
Sales	0	0
Settlements / distributions	(5,985)	0
Balance at end of period	111	984
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	101	2,084
Total Assets [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	592,856	493,362
Transfers into Level 3	22,927	0
Transfers out of Level 3	(38,420)	(1,222)
Included in earnings	53,590	89,589
Included in OCI	3,636	1,651
Purchases	136,326	141,371
Sales	0	0
Settlements / distributions	(79,329)	(131,895)
Balance at end of period	691,586	592,856
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	48,440	88,150
Total Liabilities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	815	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	10,604	98
Included in OCI	0	0
Purchases	12,715	717
Sales	0	0
Settlements / distributions	(8,846)	0
Balance at end of period	15,288	815
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	6,621	98
Corporate Debt [Member] \| Fixed Maturities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	0	1,550
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	0	1,550
Included in OCI	(95)	0
Purchases	15,957	0
Sales	0	0
Settlements / distributions	(25)	(3,100)
Balance at end of period	15,837	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
Non-Agency RMBS [Member] \| Fixed Maturities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	0	1,110
Transfers into Level 3	0	0
Transfers out of Level 3	0	(1,222)
Included in earnings	0	0
Included in OCI	0	135
Purchases	0	0
Sales	0	0
Settlements / distributions	0	(23)
Balance at end of period	0	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
CMBS [Member] \| Fixed Maturities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	4,018	4,296
Transfers into Level 3	9,447	0
Transfers out of Level 3	0	0
Included in earnings	0	0
Included in OCI	1,381	(278)
Purchases	5,027	0
Sales	0	0
Settlements / distributions	(2,110)	0
Balance at end of period	17,763	4,018
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
ABS [Member] \| Fixed Maturities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	30,799	63,975
Transfers into Level 3	1,125	0
Transfers out of Level 3	(6,165)	0
Included in earnings	0	(111)
Included in OCI	2,350	1,794
Purchases	39,800	0
Sales	0	0
Settlements / distributions	(27,878)	(34,859)
Balance at end of period	40,031	30,799
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
Hedge funds [Member] \| Other Investments [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	461,055	359,996
Transfers into Level 3	12,355	0
Transfers out of Level 3	(32,255)	0
Included in earnings	24,790	58,293
Included in OCI	0	0
Purchases	19,500	86,138
Sales	0	0
Settlements / distributions	(14,527)	(43,372)
Balance at end of period	470,918	461,055
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	24,651	58,293
Direct Lending Funds [Member] \| Other Investments [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	22,134	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	3,515	(125)
Included in OCI	0	0
Purchases	30,101	22,317
Sales	0	0
Settlements / distributions	(1,312)	(58)
Balance at end of period	54,438	22,134
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	3,515	(125)
CLO-Equities [Member] \| Other Investments [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	73,866	62,435
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	20,173	27,898
Included in OCI	0	0
Purchases	25,941	34,016
Sales	0	0
Settlements / distributions	(27,492)	(50,483)
Balance at end of period	92,488	73,866
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	20,173	27,898
Derivative [Member] \| Other Assets [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	984	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	5,112	2,084
Included in OCI	0	0
Purchases	0	(1,100)
Sales	0	0
Settlements / distributions	(5,985)	0
Balance at end of period	111	984
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	101	2,084
Derivative [Member] \| Other Liabilities [Member]
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]
Balance at beginning of period	815	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	10,604	98
Included in OCI	0	0
Purchases	12,715	717
Sales	0	0
Settlements / distributions	(8,846)	0
Balance at end of period	15,288	815
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	$ 6,621	$ 98

Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related 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).

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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