Condensed Consolidated Balance Sheets - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Document Period End Date	Sep. 30, 2019
Assets
Fixed maturities, available-for-sale, at fair value (amortized cost $2,129.0 and $2,188.2, respectively)	$ 2,189.3	$ 2,159.5
Equity securities	373.3	315.0
Other invested assets	64.6	48.8
Other invested assets, at cost	6.5	5.6
Notes receivable from affiliate	70.0	70.0
Total investments	2,703.7	2,598.9
Cash and cash equivalents	38.3	59.8
Accrued investment income and other assets	34.7	32.4
Deferred policy acquisition costs (affiliated net assumed $53.0 and $48.3, respectively)	114.3	101.9
Reinsurance recoverable on losses and loss expenses payable	7.2	5.5
Prepaid reinsurance premiums	7.5	6.6
Due from Affiliates	17.4	0.0
Current federal income taxes	6.3	5.9
Net deferred federal income taxes	46.2	77.8
Property and equipment, at cost	4.2	7.1
Total assets	2,979.8	2,895.9
Liabilities and Stockholders’ Equity
Losses and loss expenses payable (affiliated net assumed $521.5 and $593.6, respectively)	1,092.7	1,146.8
Unearned premiums (affiliated net assumed $111.7 and $112.4, respectively)	649.2	584.2
Notes payable (affiliates $15.2 and $15.2, respectively)	122.0	122.0
Pension and postretirement benefits	70.3	83.0
Due to Affiliate	0.0	22.4
Other liabilities (affiliated net assumed $13.1 and $19.9, respectively)	101.9	119.0
Total liabilities	2,036.1	2,077.4
Stockholders’ equity:
Common stock, without par value. Authorized 100.0 shares; 50.3 and 50.0 shares issued, respectively, at stated value of $2.50 per share	125.8	125.0
Treasury stock, 6.8 and 6.8 shares, respectively, at cost	(117.5)	(117.0)
Additional paid-in capital	205.2	194.2
Accumulated other comprehensive loss	(24.2)	(96.4)
Retained earnings	754.4	712.7
Total stockholders’ equity	943.7	818.5
Total liabilities and stockholders’ equity	2,979.8	2,895.9
Class A Preferred Stock [Member]
Stockholders’ equity:
Preferred stock value	0.0	0.0
Class B Preferred Stock [Member]
Stockholders’ equity:
Preferred stock value	$ 0.0	$ 0.0