Schedule IV Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Life insurance in force
Gross Amount	$ 20,440,300	$ 19,821,200	$ 19,179,800
Ceded to Other Companies	4,533,600	4,619,100	4,813,200
Assumed from Other Companies	0	0	0
Net Amount	$ 15,906,700	$ 15,202,100	$ 14,366,600
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Premiums
Gross Amount	$ 913,200	$ 949,500	$ 917,600
Ceded to Other Companies	33,300	28,700	30,400
Assumed from Other Companies	9,700	9,900	10,800
Net Amount	$ 889,600	$ 930,700	$ 898,000
Percentage of Amount Assumed to Net	1.10%	1.10%	1.20%
Property & Casualty
Premiums
Gross Amount	$ 623,000	$ 652,900	$ 689,200
Ceded to Other Companies	15,300	12,700	16,500
Assumed from Other Companies	9,700	9,900	10,800
Net Amount	$ 617,400	$ 650,100	$ 683,500
Percentage of Amount Assumed to Net	1.60%	1.50%	1.60%
Supplemental
Premiums
Gross Amount	$ 125,600	$ 130,900	$ 65,900
Ceded to Other Companies	300	200	100
Assumed from Other Companies	0	0	0
Net Amount	$ 125,300	$ 130,700	$ 65,800
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Retirement
Premiums
Gross Amount	$ 48,700	$ 38,000	$ 35,600
Ceded to Other Companies	10,200	8,300	6,500
Assumed from Other Companies	0	0	0
Net Amount	$ 38,500	$ 29,700	$ 29,100
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Life
Premiums
Gross Amount	$ 115,900	$ 127,700	$ 126,900
Ceded to Other Companies	7,500	7,500	7,300
Assumed from Other Companies	0	0	0
Net Amount	$ 108,400	$ 120,200	$ 119,600
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%