CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Common Stock	Additional Paid In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
BEGINNING BALANCE (in shares) at Dec. 31, 2022		33,429,557
BEGINNING BALANCE at Dec. 31, 2022	$ 493.5	$ 0.3	$ 228.8	$ 513.1		$ 40.6
BEGINING BALANCE, Treasury Stock (in shares) at Dec. 31, 2022					(5,123,075)
BEGINING BALANCE, Treasury Stock at Dec. 31, 2022					$ (289.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	49.3			49.3
Issuance of common stock awards to employees (in shares)		69,136
Surrender of common stock awards (in shares)					(581)
Surrender of common stock awards	0.0				$ 0.0
Share-based compensation expense	3.5		3.5
Share-based compensation issued to directors	0.1		0.1
Dividends declared	(34.9)			(34.9)
Other comprehensive income (loss), net of tax	(6.3)					(6.3)
ENDING BALANCE (in shares) at Mar. 31, 2023		33,498,693
ENDING BALANCE at Mar. 31, 2023	$ 505.2	$ 0.3	232.4	527.5		34.3
ENDING BALANCE, Treasury Stock (in shares) at Mar. 31, 2023					(5,123,656)
ENDING BALANCE, Treasury Stock at Mar. 31, 2023					$ (289.3)
BEGINNING BALANCE (in shares) at Dec. 31, 2023	33,587,701	33,587,701
BEGINNING BALANCE at Dec. 31, 2023	$ 670.3	$ 0.3	244.7	693.8		33.7
BEGINING BALANCE, Treasury Stock (in shares) at Dec. 31, 2023	(5,220,363)				(5,220,363)
BEGINING BALANCE, Treasury Stock at Dec. 31, 2023	$ (302.2)				$ (302.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	55.9			55.9
Issuance of common stock awards to employees (in shares)		70,629
Surrender of common stock awards (in shares)					(1,409)
Surrender of common stock awards	(0.2)				$ (0.2)
Share-based compensation expense	3.8		3.8
Share-based compensation issued to directors	0.2		0.2
Dividends declared	(55.5)			(55.5)
Other comprehensive income (loss), net of tax	$ 4.7					4.7
ENDING BALANCE (in shares) at Mar. 31, 2024	33,658,330	33,658,330
ENDING BALANCE at Mar. 31, 2024	$ 679.2	$ 0.3	$ 248.7	$ 694.2		$ 38.4
ENDING BALANCE, Treasury Stock (in shares) at Mar. 31, 2024	(5,221,772)				(5,221,772)
ENDING BALANCE, Treasury Stock at Mar. 31, 2024	$ (302.4)				$ (302.4)