Consolidated Statement of Stockholder's Equity (unaudited) - USD ($) $ in Millions	Total		Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2018	$ 1,684.5		$ 0.5	$ 1,685.7	$ 19.5	$ (17.7)	$ (3.5)
Beginning balance, shares at Dec. 31, 2018			48,800,000				100,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	27.7				27.7
Other comprehensive income (loss)	(0.6)					(0.6)
Dividends paid to common shareholders	(2.5)				(2.5)
Restricted shares, net - shares			0				0
Restricted shares, net - value	3.2			3.6			$ (0.4)
Shares repurchased, shares							300,000
Shares repurchased	(8.0)						$ (8.0)
Stockholders' equity, other	0.9			0.9
Ending balance at Mar. 31, 2019	1,705.2		$ 0.5	1,690.2	44.7	(18.3)	$ (11.9)
Ending balance, shares at Mar. 31, 2019			48,800,000				400,000
Beginning balance at Dec. 31, 2019	1,790.4		$ 0.5	1,686.7	122.9	(19.7)	$ 0.0
Beginning balance, shares at Dec. 31, 2019			48,300,000				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31.6				31.6
Other comprehensive income (loss)	(4.3)					(4.3)
Dividends paid to common shareholders	(2.5)				(2.5)
Restricted shares, net - shares			0				0
Restricted shares, net - value	$ 3.7			4.7			$ (1.0)
Shares repurchased, shares	56,836						100,000
Shares repurchased	$ (2.0)						$ (2.0)
Stockholders' equity, other	(0.9)			(0.9)
Ending balance at Mar. 31, 2020	$ 1,816.0	[1]	$ 0.5	$ 1,690.5	$ 152.0	$ (24.0)	$ (3.0)
Ending balance, shares at Mar. 31, 2020			48,300,000				100,000

[1] Unaudited