Reserve for Loss and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Insurance [Abstract]
Reserve for reported loss and LAE	$ 692,881		$ 692,881		$ 851,950
Reserve for losses incurred but not reported ("IBNR")	453,203		453,203		637,423
Reserve for loss and LAE	1,146,084	$ 1,567,526	1,146,084	$ 1,567,526	$ 1,489,373
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross loss and LAE reserves, January 1			1,489,373	1,893,299
Less: reinsurance recoverable on unpaid losses, January 1			562,845	592,571
Net loss and LAE reserves, January 1			926,528	1,300,728
Net incurred losses related to Current year			27,510	31,259
Net incurred losses related to Prior year			(5,493)	(23,713)
Net loss and loss adjustment expenses	17,426	10,514	22,017	7,546
Net paid losses related to Current year			(334)	(17,137)
Net paid losses related to Prior years			(319,132)	(288,202)
Net paid losses			(319,466)	(305,339)
Change in deferred gain on retroactive reinsurance			12,024	24,296
Assumed retroactive reinsurance business			7,580	0
Effect of foreign exchange rate movements			(50,574)	(21,332)
Net loss and LAE reserves, September 30	598,109	1,005,899	598,109	1,005,899
Reinsurance recoverable on unpaid losses, September 30	547,975	561,627	547,975	561,627
Gross loss and LAE reserves, September 30	$ 1,146,084	$ 1,567,526	$ 1,146,084	$ 1,567,526