Condensed Consolidated Statement of Shareholders' Equity (Unaudited) - 9 months ended Sep. 30, 2018 - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Treasury Stock, At Cost	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Dec. 31, 2017		37,094
Beginning Balance at Dec. 31, 2017	$ 211.8	$ 0.4	$ 186.5	$ (21.8)	$ 44.8	$ 1.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2.4		2.4
Issuance of restricted stock (in shares)		107
Issuance of restricted stock	0.0		(1.3)	1.3
Stock withheld for employee taxes (in shares)		(45)
Stock withheld for employee taxes	(1.4)		(0.8)	(0.6)
Proceeds from issuance of common stock (in shares)		337
Proceeds from issuance of common stock	4.2		(0.3)	4.5
Dividends declared	(49.5)				(49.5)
Repurchase of treasury shares (in shares)		(233)
Repurchase of treasury shares	(9.1)			(9.1)
Discontinued France operations cumulative translation adjustment	4.1					4.1
Change in cumulative translation adjustment	(2.8)					(2.8)
Net income	211.6				211.6
Ending Balance (in shares) at Sep. 30, 2018		37,260
Ending Balance at Sep. 30, 2018	$ 371.3	$ 0.4	$ 186.5	$ (25.7)	$ 206.9	$ 3.2