Reinsurance and Catastrophes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Losses incurred for catastrophe claims, carrying amount	$ 107,345,000	$ 61,814,000	$ 60,043,000
Percentage of coverage for catastrophe losses above retention amount, layer one	95.00%
Coverage above retention per occurrence under layer one catastrophe reinsurance	$ 25,000,000
Retention base amount per occurrence under layer one	25,000,000
Coverage above retention per occurrence under layer two catastrophe reinsurance	40,000,000
Retention base amount per occurrence under layer two	50,000,000
Coverage above retention per occurrence under layer three catastrophe reinsurance	85,000,000
Retention base amount per occurrence under layer three	90,000,000
Reinsured amount of each loss above retention in clash event	20,000,000
Amount of maximum individual life insurance risk retained	300,000
Amount of property recovery related to risk losses	$ 8,000,000
Percentage of life reinsured catastrophe risk in excess specified retention per occurrence amount	100.00%
Maximum
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount per occurrence related to catastrophe losses, layer one	$ 175,000,000
Amount of maximum group life policy insurance risk retained	125,000
Liability coverages, Company reinsured each loss above a retention per occurrence	5,000,000
Amount of life catastrophe risk in excess of per occurrence	35,000,000
Maximum | Property and Casualty
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Reinsured amount of each property loss above retention per occurrence	5,000,000
Minimum
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount per occurrence related to catastrophe losses, layer one	25,000,000
Amount of maximum group life policy insurance risk retained	100,000
Liability coverages, Company reinsured each loss above a retention per occurrence	1,000,000
Amount life catastrophe risk retention per occurrence	1,000,000
Minimum | Property and Casualty
Reinsurance Recoverable on Unpaid Insurance Reserves [Line Items]
Retention amount of each property loss per occurrence	$ 1,000,000