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Cash and Cash Equivalents and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Sep. 25, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 481,549	$ 485,928	$ 629,171
Cash equivalents	449,100	447,200
Convertible Senior Notes \| Convertible Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long-term debt	917,000
Carrying value of debt	$ 482,822	$ 467,201		$ 461,800