INVESTMENTS - Restricted assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Restricted Investments [Line Items]
Collateral in Trust for inter-company agreements	$ 2,121,522	$ 3,310,180
Collateral for secured letter of credit facility	470,051	386,451
Funds at Lloyd's	1,307,945	1,192,717
Collateral in Trust for third party agreements	1,510,416	2,085,443
Collateral in Trust for third party agreements	1,510,416	2,085,443
Securities on deposit with regulatory authorities	64,360	53,925
Total restricted investments	5,474,294	7,028,716
Syndicate 2007
Restricted Investments [Line Items]
Collateral in Trust for third party agreements	403,000	1,120,000
Collateral in Trust for third party agreements	403,000	1,120,000
Pledged cash for third party insurance and reinsurance agreements	39,000	55,000
Syndicate 1686
Restricted Investments [Line Items]
Pledged cash for third party insurance and reinsurance agreements	$ 154,000	$ 140,000

Pledged Cash For Third Party Insurance And Reinsurance Agreements

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The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for inter-company insurance and reinsurance agreements, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

No definition available.

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The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for insurance and reinsurance agreements with third parties, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

No definition available.

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- Definition

Pledged Financial Instruments, Underwriting Support

+ References

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- Definition

Restricted Investments [Line Items]

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- Definition

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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The carrying amount of securities categorized neither as held-to-maturity nor trading which serve as security for borrowings or other arrangements.

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The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for letter of credit arrangements, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

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