Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2020	18,503,805
Balance at Dec. 31, 2020	$ 6.9	$ 54.7	$ 363.3	$ (20.1)	$ 404.8	$ 1.3	$ 406.1
Net income (loss)	0.0	0.0	25.7	0.0	25.7	0.0	25.7
Other comprehensive income (loss)	$ 0.0	0.0	0.0	(10.7)	(10.7)	0.0	(10.7)
Issue stock for directors, employee benefit and stock plans (in shares)	102,681
Share-based compensation	$ 0.0	3.1	0.0	0.0	3.1	0.0	3.1
Dividends paid per common share	0.0	0.0	(4.2)	0.0	(4.2)	0.0	(4.2)
Issue Stock for Directors, Employee Benefit and Stock Plans, net of related tax withholdings	$ 0.1	1.3	0.0	0.0	1.4	0.0	1.4
Balance (in shares) at Mar. 31, 2021	18,606,486
Balance at Mar. 31, 2021	$ 7.0	59.1	384.8	(30.8)	420.1	1.3	421.4
Balance (in shares) at Dec. 31, 2020	18,503,805
Balance at Dec. 31, 2020	$ 6.9	54.7	363.3	(20.1)	404.8	1.3	406.1
Net income (loss)							35.5
Balance (in shares) at Jun. 30, 2021	18,665,065
Balance at Jun. 30, 2021	$ 7.0	64.9	390.2	(25.9)	436.2	1.3	437.5
Balance (in shares) at Mar. 31, 2021	18,606,486
Balance at Mar. 31, 2021	$ 7.0	59.1	384.8	(30.8)	420.1	1.3	421.4
Net income (loss)	0.0	0.0	9.8	0.0	9.8	0.0	9.8
Other comprehensive income (loss)	$ 0.0	0.0	0.0	4.9	4.9	0.0	4.9
Issue stock for directors, employee benefit and stock plans (in shares)	58,579
Share-based compensation	$ 0.0	3.9			3.9		3.9
Dividends paid per common share	0.0	0.0	(4.4)	0.0	(4.4)	0.0	(4.4)
Issue Stock for Directors, Employee Benefit and Stock Plans, net of related tax withholdings	$ 0.0	1.9	0.0	0.0	1.9	0.0	1.9
Balance (in shares) at Jun. 30, 2021	18,665,065
Balance at Jun. 30, 2021	$ 7.0	64.9	390.2	(25.9)	436.2	1.3	$ 437.5
Balance (in shares) at Dec. 31, 2021	18,535,116						18,535,116
Balance at Dec. 31, 2021	$ 7.0	54.1	410.6	(37.9)	433.8	1.3	$ 435.1
Net income (loss)	0.0	0.0	10.3	0.0	10.3	0.0	10.3
Other comprehensive income (loss)	$ 0.0	0.0	0.0	(4.0)	(4.0)	0.0	(4.0)
Issue stock for directors, employee benefit and stock plans (in shares)	44,700
Issue stock for directors, employee benefit and stock plans	$ 0.0	(1.3)	0.0	0.0	(1.3)	0.0	(1.3)
Share-based compensation	0.0	1.8	0.0	0.0	1.8	0.0	1.8
Dividends paid per common share	$ 0.0	0.0	(4.6)	0.0	(4.6)	0.0	(4.6)
Balance (in shares) at Mar. 31, 2022	18,579,816
Balance at Mar. 31, 2022	$ 7.0	54.6	416.3	(41.9)	436.0	1.3	$ 437.3
Balance (in shares) at Dec. 31, 2021	18,535,116						18,535,116
Balance at Dec. 31, 2021	$ 7.0	54.1	410.6	(37.9)	433.8	1.3	$ 435.1
Net income (loss)							$ 26.9
Balance (in shares) at Jun. 30, 2022	18,589,675						18,589,675
Balance at Jun. 30, 2022	$ 7.0	55.4	428.3	(58.0)	432.7	1.3	$ 434.0
Balance (in shares) at Mar. 31, 2022	18,579,816
Balance at Mar. 31, 2022	$ 7.0	54.6	416.3	(41.9)	436.0	1.3	437.3
Net income (loss)	0.0	0.0	16.6	0.0	16.6	0.0	16.6
Other comprehensive income (loss)	$ 0.0	0.0	0.0	(16.1)	(16.1)	0.0	(16.1)
Issue stock for directors, employee benefit and stock plans (in shares)	9,859
Issue stock for directors, employee benefit and stock plans	$ 0.0	(0.1)	0.0	0.0	(0.1)	0.0	(0.1)
Share-based compensation	0.0	0.9	0.0	0.0	0.9	0.0	0.9
Dividends paid per common share	$ 0.0	0.0	(4.6)	0.0	(4.6)	0.0	$ (4.6)
Balance (in shares) at Jun. 30, 2022	18,589,675						18,589,675
Balance at Jun. 30, 2022	$ 7.0	$ 55.4	$ 428.3	$ (58.0)	$ 432.7	$ 1.3	$ 434.0