CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Class A Stock
Beginning Balance (in shares) at Dec. 31, 2019		113.3				(4.9)	1.8
Beginning Balance at Dec. 31, 2019	$ 11,089.7	$ 0.1	$ 4,428.6	$ 7,379.8	$ 21.1	$ (739.9)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		3.1
Issuance of Common Stock for equity awards granted under long-term incentive plans	817.4		817.4
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.4)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(155.1)		(155.1)
Issuance/distribution of Common Stock for 401(k) Savings Plan (in shares)						0.0
Issuance/distribution of Common Stock for 401(k) Savings Plan	14.6		12.5			$ 2.1
Repurchases of Common Stock (in shares)						(0.8)
Repurchases of Common Stock	(336.0)					$ (336.0)
Stock-based compensation charges	108.0		108.0
Net income	624.6			624.6
Other comprehensive loss, net of tax	(30.2)				(30.2)
Ending Balance (in shares) at Mar. 31, 2020		116.0				(5.7)	1.8
Ending Balance at Mar. 31, 2020	12,133.0	$ 0.1	5,211.4	8,004.4	(9.1)	$ (1,073.8)	$ 0.0
Beginning Balance (in shares) at Dec. 31, 2020		121.5				(16.4)	1.8
Beginning Balance at Dec. 31, 2020	11,025.3	$ 0.1	6,716.2	10,893.0	29.3	$ (6,613.3)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		0.5
Issuance of Common Stock for equity awards granted under long-term incentive plans	93.9		93.9
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.1)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(66.4)		(66.4)
Issuance/distribution of Common Stock for 401(k) Savings Plan (in shares)						0.0
Issuance/distribution of Common Stock for 401(k) Savings Plan	10.0		8.5			$ 1.5
Repurchases of Common Stock (in shares)						(0.7)
Repurchases of Common Stock	(323.5)					$ (323.5)
Stock-based compensation charges	135.6		135.6
Net income	1,115.2			1,115.2
Other comprehensive loss, net of tax	(13.1)				(13.1)
Ending Balance (in shares) at Mar. 31, 2021		121.9				(17.1)	1.8
Ending Balance at Mar. 31, 2021	$ 11,977.0	$ 0.1	$ 6,887.8	$ 12,008.2	$ 16.2	$ (6,935.3)	$ 0.0