Unpaid Losses and Loss Adjustment Expenses - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year adjustments	$ 5,778,000	$ 3,749,000
Commercial Lines
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year adjustments	5,200,000	$ 3,700,000
Personal Lines
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year adjustments	612,000
Hospitality
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year adjustments	2,700,000
Small Business Lines
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year adjustments	$ 2,500,000