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Investment Information - Restricted assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Restricted Assets [Line Items]
Restricted assets	$ 8,249,732	$ 8,733,309	[1]
Collateral or guarantees - affiliated transactions
Restricted Assets [Line Items]
Restricted assets	4,223,955	4,643,334
Collateral or guarantees - third party agreements
Restricted Assets [Line Items]
Restricted assets	2,721,160	3,083,324
Deposits with US regulatory authorities
Restricted Assets [Line Items]
Restricted assets	798,100	827,552
Deposits with non-US regulatory authorities
Restricted Assets [Line Items]
Restricted assets	$ 506,517	179,099
Somers Holdings Ltd.
Restricted Assets [Line Items]
Restricted assets		$ 1,036,000
[1] 2020 balances included $1.036 billion related to Somers.

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- Definition

Assets, consisting primarily of fixed maturities, that the Company is required to maintain with various regulatory authorities to support its insurance and reinsurance operations. The Company's insurance and reinsurance subsidiaries maintain assets in trust accounts as collateral for insurance and reinsurance transactions with affiliated companies and also have investments in segregated portfolios primarily to provide collateral or guarantees for letters of credit to third parties.

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