Earnings (Loss) Per Share (Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income from continuing operations		$ 279.9		$ 101.0		$ 47.7	$ 193.1
Loss from discontinued operations, net of income taxes		(0.1)		(0.2)		(0.2)	(0.3)
NET INCOME		$ 279.8	$ (232.3)	$ 100.8	$ 92.0	$ 47.5	$ 192.8
Basic weighted average common shares outstanding (in shares)		87.9		89.9		89.0	90.2
Dilutive effect of stock options and unvested RSUs (in shares)		0.2		0.3		0.0	0.2
Diluted weighted average common shares outstanding (in shares)		88.1		90.2		89.0	90.4
Basic earnings (loss) per share amounts:
Continuing operations (in dollars per share)	[1]	$ 3.18		$ 1.12		$ 0.54	$ 2.14
Discontinued operations (in dollars per share)	[1]	0		0		0	0
Net income (in dollars per share)	[1]	3.18		1.12		0.53	2.14
Diluted earnings (loss) per share amounts:
Continuing operations (in dollars per share)	[1]	3.18		1.12		0.54	2.14
Discontinued operations (in dollars per share)	[1]	0		0		0	0
Net income (in dollars per share)	[1]	$ 3.18		$ 1.12		$ 0.53	$ 2.13

[1] Earnings per share amounts are calculated discretely and therefore may not add up to the total due to rounding.