Variable Interest Entities	6 Months Ended
Jun. 30, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES Effective January 1, 2012, the Company formed and launched a new managed joint venture, Upsilon Reinsurance Ltd. (“Upsilon Re”), a Bermuda domiciled special purpose insurer ("SPI"), to provide additional capacity to the worldwide aggregate and per-occurrence retrocessional property catastrophe excess of loss market for the 2012 underwriting year. The original business was written by Renaissance Reinsurance of Europe ("ROE"), a wholly owned subsidiary of RenaissanceRe, and included $37.4 million of gross premiums written. A portion of this business was in turn ceded to Upsilon Re under a fully-collateralized retrocessional reinsurance contract, effective January 1, 2012. In conjunction with the formation and launch of Upsilon Re, $16.8 million of non-voting Class B shares were sold to external investors, and the Company invested $48.8 million in Upsilon Re's non-voting Class B shares, representing a 74.5% ownership interest in Upsilon Re. The Class B shareholders will participate in substantially all of the profits or losses of Upsilon Re while the Class B shares remain outstanding. The holders of Class B shares indemnify Upsilon Re against losses relating to insurance risk and therefore these shares have been accounted for as prospective reinsurance under Financial Accounting Standards Board Accounting Standards Codification Topic Financial Services - Insurance. In addition, another third party investor supplied $17.6 million of capital through a reinsurance participation with ROE alongside Upsilon Re. Inclusive of the third party quota share agreement, the Company has a 61.4% participation in the original risks assumed by ROE. Both Upsilon Re and the third party reinsurance participation related to Upsilon Re are managed by RUM in return for an expense override, as well as a potential underwriting profit commission. Upsilon Re is considered a VIE and the Company is considered the primary beneficiary. As a result, Upsilon Re is consolidated by the Company and all significant inter-company transactions have been eliminated. The Company's ownership interest in Upsilon Re could change over time, perhaps materially so, and the Company may also elect to underwrite additional risks within Upsilon Re and to write business within Upsilon Re in future underwriting years. Effective June 1, 2012, the Company formed and launched a new managed joint venture, Timicuan Reinsurance III Limited (“Tim Re III”), a Bermuda domiciled SPI, to provide collateralized reinsurance in respect of a portfolio of Florida reinstatement premium protection ("RPP") contracts. The original business was written by Renaissance Reinsurance and DaVinci, and included $41.1 million of gross premiums written incepting June 1, 2012 and Renaissance Reinsurance and DaVinci ceded $37.7 million to Tim Re III under a fully-collateralized reinsurance contract. In conjunction with the formation and launch of Tim Re III, $44.8 million of non-voting Class B shares were sold to external investors, and the Company invested an additional $10.3 million in Tim Re III's non-voting Class B shares, representing an 18.6% ownership interest in Tim Re III. The Class B shareholders will participate in substantially all of the profits or losses of Tim Re III while the Class B shares remain outstanding. The holders of Class B shares indemnify Tim Re III against losses relating to insurance risk and therefore these shares have been accounted for as prospective reinsurance under Financial Accounting Standards Board Accounting Standards Codification Topic Financial Services - Insurance. In addition, another third party investor supplied $5.2 million of capital through a reinsurance participation with Renaissance Reinsurance and DaVinci, alongside Tim Re III. Both Tim Re III and the third party reinsurance participation related to Tim Re III are managed by RUM in return for a potential underwriting profit commission. Tim Re III is considered a VIE and the Company is considered the primary beneficiary. As a result, Tim Re III is consolidated by the Company and all significant inter-company transactions have been eliminated.

VARIABLE INTEREST ENTITIES

Effective January 1, 2012, the Company formed and launched a new managed joint venture, Upsilon Reinsurance Ltd. (“Upsilon Re”), a Bermuda domiciled special purpose insurer ("SPI"), to provide additional capacity to the worldwide aggregate and per-occurrence retrocessional property catastrophe excess of loss market for the 2012 underwriting year. The original business was written by Renaissance Reinsurance of Europe ("ROE"), a wholly owned subsidiary of RenaissanceRe, and included $37.4 million of gross premiums written. A portion of this business was in turn ceded to Upsilon Re under a fully-collateralized retrocessional reinsurance contract, effective January 1, 2012. In conjunction with the formation and launch of Upsilon Re, $16.8 million of non-voting Class B shares were sold to external investors, and the Company invested $48.8 million in Upsilon Re's non-voting Class B shares, representing a 74.5% ownership interest in Upsilon Re. The Class B shareholders will participate in substantially all of the profits or losses of Upsilon Re while the Class B shares remain outstanding. The holders of Class B shares indemnify Upsilon Re against losses relating to insurance risk and therefore these shares have been accounted for as prospective reinsurance under Financial Accounting Standards Board Accounting Standards Codification Topic Financial Services - Insurance. In addition, another third party investor supplied $17.6 million of capital through a reinsurance participation with ROE alongside Upsilon Re. Inclusive of the third party quota share agreement, the Company has a 61.4% participation in the original risks assumed by ROE. Both Upsilon Re and the third party reinsurance participation related to Upsilon Re are managed by RUM in return for an expense override, as well as a potential underwriting profit commission. Upsilon Re is considered a VIE and the Company is considered the primary beneficiary. As a result, Upsilon Re is consolidated by the Company and all significant inter-company transactions have been eliminated.

The Company's ownership interest in Upsilon Re could change over time, perhaps materially so, and the Company may also elect to underwrite additional risks within Upsilon Re and to write business within Upsilon Re in future underwriting years.

Effective June 1, 2012, the Company formed and launched a new managed joint venture, Timicuan Reinsurance III Limited (“Tim Re III”), a Bermuda domiciled SPI, to provide collateralized reinsurance in respect of a portfolio of Florida reinstatement premium protection ("RPP") contracts. The original business was written by Renaissance Reinsurance and DaVinci, and included $41.1 million of gross premiums written incepting June 1, 2012 and Renaissance Reinsurance and DaVinci ceded $37.7 million to Tim Re III under a fully-collateralized reinsurance contract. In conjunction with the formation and launch of Tim Re III, $44.8 million of non-voting Class B shares were sold to external investors, and the Company invested an additional $10.3 million in Tim Re III's non-voting Class B shares, representing an 18.6% ownership interest in Tim Re III. The Class B shareholders will participate in substantially all of the profits or losses of Tim Re III while the Class B shares remain outstanding. The holders of Class B shares indemnify Tim Re III against losses relating to insurance risk and therefore these shares have been accounted for as prospective reinsurance under Financial Accounting Standards Board Accounting Standards Codification Topic Financial Services - Insurance. In addition, another third party investor supplied $5.2 million of capital through a reinsurance participation with Renaissance Reinsurance and DaVinci, alongside Tim Re III. Both Tim Re III and the third party reinsurance participation related to Tim Re III are managed by RUM in return for a potential underwriting profit commission. Tim Re III is considered a VIE and the Company is considered the primary beneficiary. As a result, Tim Re III is consolidated by the Company and all significant inter-company transactions have been eliminated.