Debt - Additional Information (Details)		1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 20, 2018 USD ($) trading_day business_day $ / shares	Nov. 30, 2018 USD ($)	Sep. 30, 2022 USD ($) $ / shares	Sep. 30, 2021 USD ($) $ / shares	Sep. 30, 2022 USD ($) $ / shares	Sep. 30, 2021 USD ($) $ / shares	Jan. 01, 2022	Dec. 31, 2021 USD ($)	Jun. 26, 2015 USD ($)
Debt Instrument [Line Items]
Conversion price (in dollars per share) | $ / shares			$ 101.38	$ 101.38	$ 101.38	$ 101.38
Amortization of debt discount					$ 1,588,000	$ 8,551,000
Unamortized debt issuance costs			$ 1,466,000		1,466,000			$ 2,363,000
Aggregate principal amount			316,222,000		316,222,000			316,245,000
Federal Funds
Debt Instrument [Line Items]
Credit facility basis point (as a percent)		0.50%
London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Credit facility basis point (as a percent)		1.00%
2023 Convertible Notes
Debt Instrument [Line Items]
Exceeded principal amount			200,700,000		200,700,000
Fundamental change repurchase price percent (as a percent)	100.00%
Aggregate principal amount			316,222,000		316,222,000			316,245,000
2023 Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Principal amount	$ 316,300,000
Interest rate (as a percent)	2.00%
Conversion price (in dollars per share) | $ / shares	$ 101.38
Interest expense			1,600,000	$ 4,700,000	1,600,000	4,700,000
Amortization of debt discount				$ 2,400,000		$ 7,100,000
2023 Convertible Notes | Convertible Debt | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Threshold trading days | trading_day	20
Consecutive trading days | trading_day	30
Redemption price percentage	130.00%
2023 Convertible Notes | Convertible Debt | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Consecutive trading days | trading_day	5
Redemption price percentage	98.00%
Debt instrument business days | business_day	5
2023 Convertible Notes | Senior Notes
Debt Instrument [Line Items]
Interest rate (as a percent)							2.00%
Debt conversion ratio (in shares)	0.0098643
Convertible Note Due 2023, Par Value
Debt Instrument [Line Items]
Principal amount	$ 1,000
Credit Facility | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity									$ 550,000,000
Debt issuance costs		$ 1,700,000
Borrowings outstanding			0		0			0
Borrowing limit used			400,000		400,000
Unamortized debt issuance costs			$ 500,000		$ 500,000			$ 900,000
Credit Facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)					0.20%
Fronting fees (as a percent)					1.25%
Credit Facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Commitment fee (as a percent)					0.35%
Fronting fees (as a percent)					2.00%
Credit Facility | Line of Credit | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread (as a percent)		1.25%
Credit Facility | Line of Credit | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread (as a percent)		2.00%
Credit Facility | Line of Credit | Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread (as a percent)		0.25%
Credit Facility | Line of Credit | Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread (as a percent)		1.00%