Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in-Capital	Accumulated Other Comprehensive Loss	Company Shares Held by SERP	Retained Earnings	Non-controlling Interest
Balance at Dec. 31, 2019	$ 601.8					$ 507.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46.0
Balance (in shares) at Dec. 31, 2020		22,611,976
Balance at Dec. 31, 2020	641.5	$ 4.5	$ 127.8	$ (33.5)	$ (1.5)	543.7	$ 0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8.5					8.5	0.0
Other comprehensive income (loss)	(0.8)			(0.7)			(0.1)
Dividends	(2.5)					(2.5)
Share-based compensation	1.4		1.4
Issuance of common stock under incentive plan (in shares)		103,541
Withholding tax paid upon equity award vesting	(3.0)		(3.0)
Deferred compensation programs' transactions, net	0.2		0.1		0.1
Balance (in shares) at Mar. 31, 2021		22,715,517
Balance at Mar. 31, 2021	645.3	$ 4.5	126.3	(34.2)	(1.4)	549.7	0.4
Balance (in shares) at Dec. 31, 2020		22,611,976
Balance at Dec. 31, 2020	641.5	$ 4.5	127.8	(33.5)	(1.5)	543.7	0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16.8
Balance at Jun. 30, 2021	656.9					555.5
Balance (in shares) at Dec. 31, 2020		22,611,976
Balance at Dec. 31, 2020	641.5	$ 4.5	127.8	(33.5)	(1.5)	543.7	0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	25.8
Balance at Sep. 30, 2021	660.4					562.0
Balance (in shares) at Dec. 31, 2020		22,611,976
Balance at Dec. 31, 2020	641.5	$ 4.5	127.8	(33.5)	(1.5)	543.7	0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 15.9
Balance (in shares) at Dec. 31, 2021	22,767,052	22,767,052
Balance at Dec. 31, 2021	$ 651.3	$ 4.5	130.6	(32.4)	(1.2)	549.3	0.5
Balance (in shares) at Mar. 31, 2021		22,715,517
Balance at Mar. 31, 2021	645.3	$ 4.5	126.3	(34.2)	(1.4)	549.7	0.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8.3
Balance at Jun. 30, 2021	656.9					555.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9.0
Balance at Sep. 30, 2021	$ 660.4					562.0
Balance (in shares) at Dec. 31, 2021	22,767,052	22,767,052
Balance at Dec. 31, 2021	$ 651.3	$ 4.5	130.6	(32.4)	(1.2)	549.3	0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4.1					4.1
Other comprehensive income (loss)	4.2			4.1			0.1
Dividends	(2.8)					(2.8)
Share-based compensation	1.8		1.8
Issuance of common stock under incentive plan (in shares)		69,995
Issuance of common stock under incentive plan	0.1	$ 0.1
Withholding tax paid upon equity award vesting	$ (1.3)		(1.3)
Balance (in shares) at Mar. 31, 2022	22,837,047	22,837,047
Balance at Mar. 31, 2022	$ 657.4	$ 4.6	$ 131.1	$ (28.3)	$ (1.2)	$ 550.6	$ 0.6