Consolidated Statements of Changes in Shareholders' Deficit - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Shares [Member]	Treasury Stock [Member]	Paid-in Capital in Excess of par Value [Member]	Paid-in Capital in Excess of par Value [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balance at Dec. 31, 2019	$ (390.0)		$ 0.1	$ (328.9)	$ 366.6		$ (212.5)	$ (215.3)
Issuance of common shares from exercise of stock options, SARs, restricted stock units, employee stock purchase plan, and other	3.5				3.5
Additional capital from share-based compensation	51.0				51.0
Repurchases of 19.0, 21.0 and 4.1 common shares in 2020, 2021 and 2022 respectively	(923.5)				(78.8)			(844.7)
Net income	372.6							372.6
Foreign currency translation adjustment, net of income taxes of $1.1 (2022), 0.2 (2021), and $(2.0) (2020)	33.2						33.2
Unrealized (loss) gain on derivatives, net of income taxes of $ $ - (2022), $ - (2021), and $(0.4) (2020)	(2.9)						(2.9)
Ending balance at Dec. 31, 2020	(856.1)		0.1	(328.9)	342.3		(182.2)	(687.4)
Issuance of common shares from exercise of stock options, SARs, restricted stock units, employee stock purchase plan, and other	4.2				4.2
Additional capital from share-based compensation	54.1				54.1
Repurchases of 19.0, 21.0 and 4.1 common shares in 2020, 2021 and 2022 respectively	(1,011.3)				(82.5)			(928.8)
Net income	447.2							447.2
Foreign currency translation adjustment, net of income taxes of $1.1 (2022), 0.2 (2021), and $(2.0) (2020)	(33.2)						(33.2)
Unrealized (loss) gain on derivatives, net of income taxes of $ $ - (2022), $ - (2021), and $(0.4) (2020)	3.6						3.6
Ending balance at Dec. 31, 2021	(1,391.5)		0.1	(328.9)	318.1		(211.8)	(1,169.0)
Accumulated deficit	(1,169.0)
Issuance of common shares from exercise of stock options, SARs, restricted stock units, employee stock purchase plan, and other	4.1				4.1
Additional capital from share-based compensation	44.4				44.4
Repurchases of 19.0, 21.0 and 4.1 common shares in 2020, 2021 and 2022 respectively	(146.7)				(23.9)			(122.8)
Retirement of treasury stock	0.0			328.9	(17.3)			(311.6)
Net income	321.3							321.3
Foreign currency translation adjustment, net of income taxes of $1.1 (2022), 0.2 (2021), and $(2.0) (2020)	(36.6)						(36.6)
Unrealized (loss) gain on derivatives, net of income taxes of $ $ - (2022), $ - (2021), and $(0.4) (2020)	(1.8)						(1.8)
Ending balance at Dec. 31, 2022	(1,265.9)		$ 0.1	$ (0.0)	$ 188.7		$ (250.2)	$ (1,204.5)
Accumulated deficit	$ (1,204.5)	$ (59.1)				$ (136.7)			$ 77.6