Financial Instruments - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Share price (in dollars per share)	$ 50.10
Accrued interest	$ 148,000	$ 108,000
Available-for-sale, credit loss	0	$ 0
1.75% Convertible Senior Notes due 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregated principal amount	23,512,000
0% Convertible Senior Notes due 2025
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregated principal amount	661,250,000
0.5% Convertible Senior Notes Due 2027
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregated principal amount	$ 575,000,000
Interest Rate Lock Commitments | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan commitments, term	30 days
Interest Rate Lock Commitments | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan commitments, term	90 days