Losses and Loss Adjustment Expenses - Change in Fair Value Option Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Insurance [Abstract]
Changes in fair value - fair value option	$ 5	$ (4)

Fair value adjustment to prior period incurred losses, where the fair value option has been elected. Includes discount rate and risk margin components.

No definition available.

Name:	esgr_ClaimsAndClaimsAdjustmentExpenseChangeInFairValuePriorYears
Namespace Prefix:	esgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration