Schedule III. Supplementary Insurance Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred Policy Acquisition Costs		$ 87,094	$ 94,292	$ 92,796
Future Policy Benefits, Losses, Claims and Loss Expenses		1,578,131	1,421,754	1,312,483
Unearned Premiums		464,845	505,162	492,918
Earned Premium Revenue		1,055,082	1,086,972	1,050,454
Investment Income, Net		39,670	60,414	65,557
Benefits, Claims, Losses and Settlement Expenses		869,467	830,172	747,457
Amortization of Deferred Policy Acquisition Costs		210,252	216,199	208,127
Other Underwriting Expenses		143,332	137,415	145,337
Interest on Policyholders' Accounts		0	0	4,499
Premiums Written		1,011,350	1,096,730	1,061,664
Property and casualty business
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred Policy Acquisition Costs		87,094	94,292	92,796
Future Policy Benefits, Losses, Claims and Loss Expenses		1,578,131	1,421,754	1,312,483
Unearned Premiums		464,845	505,162	492,918
Earned Premium Revenue		1,055,082	1,086,972	1,037,451
Investment Income, Net		39,670	60,414	52,894
Benefits, Claims, Losses and Settlement Expenses		869,467	830,172	731,611
Amortization of Deferred Policy Acquisition Costs		210,252	216,199	206,232
Other Underwriting Expenses		143,332	137,415	141,473
Interest on Policyholders' Accounts		0	0	0
Premiums Written		1,011,350	1,096,730	1,061,664
Discontinued Operations | Life Insurance
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred Policy Acquisition Costs	[1]	0	0	0
Future Policy Benefits, Losses, Claims and Loss Expenses	[1]	0	0	0
Unearned Premiums	[1]	0	0	0
Earned Premium Revenue	[1]	0	0	13,003
Investment Income, Net	[1]	0	0	12,663
Benefits, Claims, Losses and Settlement Expenses	[1]	0	0	15,846
Amortization of Deferred Policy Acquisition Costs	[1]	0	0	1,895
Other Underwriting Expenses	[1]	0	0	3,864
Interest on Policyholders' Accounts	[1]	0	0	4,499
Premiums Written	[1]	$ 0	$ 0	$ 0

[1] Annuity deposits are included in future policy benefits, losses, claims and loss expenses