Convertible Senior Notes - Additional Information (Details) - 0.125% Convertible Senior Notes due 2025 $ / shares in Units, shares in Millions		9 Months Ended
Jun. 02, 2020 USD ($)	Sep. 30, 2020 USD ($) d $ / shares shares
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount	$ 747,500,000	$ 747,500,000
Debt instrument, interest rate	0.125%
Debt instrument, net proceeds from sale of notes	$ 730,200,000
Debt instrument, date of first required payment	Dec. 15, 2020
Debt instrument, maturity date	Jun. 15, 2025
Debt instrument, payment terms		The 2025 Notes bear interest at a rate of 0.125% per year, payable semiannually in arrears on June 15 and December 15 of each year, beginning on December 15, 2020.
Debt Instrument, frequency of interest payment		semiannually
Debt instrument, convertible carrying amount of equity component		$ 177,169,000
Debt issuance costs		17,300,000
Issuance cost attributable to liability component		13,200,000
Issuance cost attributable to equity component		$ 4,099,000
Debt instrument, effective interest rate		5.97%
Debt instrument, estimated fair value		$ 994,100,000
Initial strike price per share of capped calls \| $ / shares		$ 92.30
Initial cap price per share of capped calls \| $ / shares		$ 151.04
Cost incurred to purchase capped calls		$ 89,600,000
Redemption, On or After June 20, 2023, and Prior to 31st Scheduled Trading Day
Debt Instrument [Line Items]
Debt instrument redemption price percentage of principal amount redeemed		100.00%
Class A Common Stock
Debt Instrument [Line Items]
Common stock covered under capped calls \| shares		8.1
Class A Common Stock \| Redemption, On or After June 20, 2023, and Prior to 31st Scheduled Trading Day
Debt Instrument [Line Items]
Debt instrument, trading days \| d		20
Debt instrument, consecutive trading days \| d		30
Class A Common Stock \| Minimum \| Redemption, On or After June 20, 2023, and Prior to 31st Scheduled Trading Day
Debt Instrument [Line Items]
Debt instrument, threshold percentage of conversion price		130.00%
Conversion Preceding March 15, 2025, Scenario One
Debt Instrument [Line Items]
Debt instrument, trading days \| d		20
Debt instrument, consecutive trading days \| d		30
Debt instrument, threshold percentage of conversion price		130.00%
Conversion Preceding March 15, 2025, Scenario Two
Debt Instrument [Line Items]
Debt instrument, consecutive trading days \| d		10
Number of consecutive business days after any five consecutive trading day period during the note measurement period \| d		5
Debt instrument, principal amount denomination used in conversion		$ 1,000
Debt instrument, convertible, threshold maximum percentage of product of last reported sale price of common stock		98.00%
Conversion, On or After March 15, 2025
Debt Instrument [Line Items]
Debt instrument, principal amount denomination used in conversion		$ 1,000
Debt instrument, conversion price per share \| $ / shares		$ 92.30
Conversion, On or After March 15, 2025 \| Class A Common Stock
Debt Instrument [Line Items]
Debt instrument, principal amount denomination used in conversion		$ 1,000
Debt instrument, conversion ratio		10.8338
Debt instrument, conversion price per share \| $ / shares		$ 92.30

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