Income Taxes - Components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred income tax assets:
Net operating loss	$ 76,665	$ 87,960
Discounting of net loss reserves	77,556	72,001
Net unearned premium reserve	96,581	75,483
Compensation liabilities	55,269	28,062
Foreign tax credit carryforward	16,738	20,058
Bad debt reserves	17,365	10,252
Depreciation and amortization	141,409	115,041
Lease liability	26,681	21,453
Net unrealized decline of investments	192,949	0
Lloyds year of account deferral	1,385	0
Other, net	14,450	703
Deferred tax assets before valuation allowance	717,048	431,013
Valuation allowance	(6,968)	(43,953)
Deferred tax assets net of valuation allowance	710,080	387,060
Deferred income tax liabilities:
Deposit accounting liability	(2,658)	(1,578)
Goodwill and intangibles	(38,905)	(70,549)
Lloyds year of account deferral	0	(12,514)
Contingency reserve	(43,870)	(49,486)
Deferred policy acquisition costs	(63,708)	(25,612)
Investment related	(9,225)	(7,492)
Net unrealized appreciation of investments	0	(8,377)
Right-of-use asset	(20,781)	(17,406)
Total deferred tax liabilities	(179,147)	(193,014)
Net deferred income tax assets	$ 530,933	$ 194,046