Segment - Schedule of Premiums Written (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Total gross written premiums	$ 1,743,232	$ 1,459,829	$ 1,143,952
Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	1,743,249	1,459,847	1,138,627
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Effects of Reinsurance [Line Items]
Total gross written premiums	(17)	(18)	5,325
Industry Solutions \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	317,198	305,476	267,628
Global Property & Agriculture \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	311,402	273,191	205,081
Captives \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	241,902	167,624	124,286
Programs \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	218,407	178,726	163,653
Accident & Health \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	173,073	151,701	130,808
Transactional E&S \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	169,053	122,508	75,098
Professional Lines \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	159,785	154,565	93,011
Surety \| Operating Segments
Effects of Reinsurance [Line Items]
Total gross written premiums	$ 152,429	$ 106,056	$ 79,062