Liability for Losses and Loss Expenses, Reconciliation of Net Incurred and Paid Claims Development Tables to Liability for Claims and Claim Adjustment Expenses (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	$ 581,531,000
Reinsurance recoverable	428,978,000
Unallocated loss adjustment expenses	67,111,000
Gross liability for unpaid losses and loss expenses	1,077,620,301	$ 962,007,437	$ 869,673,849	$ 814,665,224
Personal Automobile [Member]
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	101,429,000
Reinsurance recoverable	110,925,000
Homeowners [Member]
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	22,960,000
Reinsurance recoverable	13,200,000
Commercial Automobile [Member]
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	160,817,000
Reinsurance recoverable	107,037,000
Commercial Multi-Peril [Member]
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	157,593,000
Reinsurance recoverable	98,848,000
Workers Compensation [Member]
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	113,779,000
Reinsurance recoverable	92,352,000
Other [Member]
Reconciliation of Net Incurred and Paid Claims Development [Abstract]
Net outstanding liabilities	24,953,000
Reinsurance recoverable	$ 6,616,000