Nature of Operations and Basis of Presentation - Deferred Policy Acquisition Costs (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of period	$ 104,225
Underwriting costs deferred	202,768
Amortization of deferred policy acquisition costs	(181,700)
Recorded asset at ending of period	$ 125,292