Reinsurance and Catastrophes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Losses incurred for catastrophe claims, carrying amount	$ 84,400	$ 52,000	$ 107,300
Percentage of coverage for catastrophe losses above retention amount, layer one	95.00%
Coverage above retention per occurrence under layer one catastrophe reinsurance	$ 25,000
Retention base amount per occurrence under layer one	25,000
Coverage above retention per occurrence under layer two catastrophe reinsurance	40,000
Retention base amount per occurrence under layer two	50,000
Coverage above retention per occurrence under layer three catastrophe reinsurance	85,000
Retention base amount per occurrence under layer three	90,000
Reinsured amount of each loss above retention in clash event	20,000
Amount of property recovery related to risk losses	8,000
Amount of maximum individual life insurance risk retained	$ 500
Percentage of life reinsured catastrophe risk in excess specified retention per occurrence amount	100.00%
Minimum
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount per occurrence related to catastrophe losses, layer one	$ 25,000
Liability coverages, Company reinsured each loss above a retention per occurrence	1,000
Amount of group life policy insurance risk retained	100
Amount life catastrophe risk retention per occurrence	1,000
Minimum | Property and Casualty segment
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount of each property loss per occurrence	1,000
Maximum
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount per occurrence related to catastrophe losses, layer one	175,000
Liability coverages, Company reinsured each loss above a retention per occurrence	5,000
Amount of group life policy insurance risk retained	125
Amount life catastrophe risk retention per occurrence	35,000
Maximum | Property and Casualty segment
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount of each property loss per occurrence	$ 5,000