Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Shares	Common Stock and Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance (in shares) at Dec. 31, 2019		335.9
Balance at Dec. 31, 2019	$ 4,610.6		$ 7,370.5	$ (18.5)	$ (2,741.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	20.4				20.4
Other comprehensive income (loss), net	(40.7)			(40.7)
Issuance of common stock (in shares)		5.6
Issuance of common stock	27.1		27.1
Repurchase and retirement of common stock (in shares)		(10.5)
Repurchase and retirement of common stock	(243.2)		(132.8)		(110.4)
Purchase of forward contract under accelerated share repurchase program ("ASR")	40.0		40.0
Share-based compensation expense	42.0		42.0
Payments of cash dividends	(65.5)		(65.5)
Balance (in shares) at Mar. 31, 2020		331.0
Balance at Mar. 31, 2020	4,390.7		7,281.3	(59.2)	(2,831.4)
Balance (in shares) at Dec. 31, 2020		327.7
Balance at Dec. 31, 2020	4,543.5		7,156.9	55.6	(2,669.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(31.1)				(31.1)
Other comprehensive income (loss), net	25.7			25.7
Issuance of common stock (in shares)		5.0
Issuance of common stock	31.1		31.1
Repurchase and retirement of common stock (in shares)		(5.3)
Repurchase and retirement of common stock	(131.9)		(69.4)		(62.5)
Share-based compensation expense	57.5		57.5
Payments of cash dividends	(65.2)		(65.2)
Balance (in shares) at Mar. 31, 2021		327.4
Balance at Mar. 31, 2021	$ 4,429.6		$ 7,110.9	$ 81.3	$ (2,762.6)