Schedule IV Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Life insurance in force
Gross Amount	$ 18,277,691	$ 17,564,270	$ 17,025,125
Ceded to Other Companies	4,505,208	4,295,412	4,065,449
Assumed from Other Companies	0	0	0
Net Amount	$ 13,772,483	$ 13,268,858	$ 12,959,676
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Premiums
Gross Amount	$ 841,147	$ 812,099	$ 777,651
Ceded to Other Companies	28,837	22,036	22,826
Assumed from Other Companies	5,023	4,640	4,321
Net Amount	$ 817,333	$ 794,703	$ 759,146
Percentage of Amount Assumed to Net	0.60%	0.60%	0.60%
Property and Casualty
Premiums
Gross Amount	$ 682,478	$ 658,960	$ 632,372
Ceded to Other Companies	21,767	15,337	16,179
Assumed from Other Companies	5,023	4,640	4,321
Net Amount	$ 665,734	$ 648,263	$ 620,514
Percentage of Amount Assumed to Net	0.80%	0.70%	0.70%
Retirement
Premiums
Gross Amount	$ 31,269	$ 28,003	$ 24,937
Ceded to Other Companies	0	0	0
Assumed from Other Companies	0	0	0
Net Amount	$ 31,269	$ 28,003	$ 24,937
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Life
Premiums
Gross Amount	$ 127,400	$ 125,136	$ 120,342
Ceded to Other Companies	7,070	6,699	6,647
Assumed from Other Companies	0	0	0
Net Amount	$ 120,330	$ 118,437	$ 113,695
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%