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Summary of Significant Accounting Policies Fair Values of Derivative Instruments Included on Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		$ 227.0	$ 224.7
Liability Derivatives Fair Value		97.5	11.3
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax		(123.3)	(20.4)	$ 48.9
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	$ 111.3
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		41.4	31.6
Liability Derivatives Fair Value		79.5	6.4
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		185.6	193.1
Liability Derivatives Fair Value		18.0	4.9
Gain (Loss) Recognized in Income on Derivative		(0.6)	86.0
Royalty Arrangement
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 1,200.0
Period covered by hedge	18 months
Foreign currency \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivative		(29.0)	14.2
Foreign currency \| Prepaid expenses and other current assets \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value			10.0
Foreign currency \| Prepaid expenses and other current assets \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value			12.4
Foreign currency \| Accrued payroll and other liabilities \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value		64.5	5.2
Foreign currency \| Accrued payroll and other liabilities \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value		9.4	4.8
Foreign currency \| Miscellaneous other assets \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		5.6	9.5
Foreign currency \| Other long- term liabilities \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value		15.0	1.2
Interest rate \| Accrued payroll and other liabilities \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value			0.0
Interest rate \| Miscellaneous other assets \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		35.8	12.1
Interest rate \| Other long- term liabilities \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value			0.0
Equity \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivative		44.4	71.8
Equity \| Prepaid expenses and other current assets \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		185.6	1.6
Equity \| Accrued payroll and other liabilities \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value		8.6	0.1
Equity \| Miscellaneous other assets \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value			$ 179.1
Fair Value Hedging [Member] \| Interest Rate Risk [Member]
Derivatives, Fair Value [Line Items]
Increase (Decrease) in Fair Value of Interest Rate Fair Value Hedging Instruments	$ 35.8
Gain (Loss) Recognized in Income on Derivative		$ 23.7
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,100.0
Intercompany Debt [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Nonderivative Instruments	843.2
Debt [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Nonderivative Instruments	$ 13,300.0