Earnings Per Share - Schedule of Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024	[2]
Numerator:
Net income available to common shareholders	[1]	$ 21.6	$ 18.2
Denominator – Weighted-average common shares outstanding (in thousands):
Basic		16,116	16,027	[3]
Add: dilutive effect of non-vested common shares, restricted stock units and performance shares	[4]	283	203
Diluted		16,399	16,230	[3]
Net income per common share, Basic:		$ 1.34	$ 1.13	[3]
Net income per common share, Diluted:		$ 1.31	$ 1.12	[3]

[1] Represents Net income less distributed and undistributed earnings allocated to non-vested restricted stock awards that contain non-forfeitable rights to dividends.

[2] Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 14 for further discussion.

[3] Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 14 for further discussion.

[4] Quantities in the following discussion are denoted in whole shares. During the quarters ended March 31, 2025 and March 31, 2024, approximately 4,000 and 2,200 shares, respectively, were excluded from the weighted-average diluted shares computation as their inclusion would have been anti‑dilutive.