Convertible Notes - Narrative (Details) - USD ($)							3 Months Ended		12 Months Ended
	Jul. 15, 2022	Jul. 14, 2022	Mar. 11, 2019	Mar. 01, 2019	May 18, 2018	Apr. 11, 2017	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022
Debt Instrument [Line Items]
Net realized (losses) on extinguishment of debt							$ (28,000)	$ (5,357,000)
Outstanding amount							2,670,175,000		$ 2,769,156,000
Repayments of convertible debt							60,501,000	51,872,000
Debt financing costs							15,223,000		10,801,000
Convertible Notes
Debt Instrument [Line Items]
Outstanding amount							156,168,000		216,669,000
Unamortized discount							1,376,000		1,511,000
Debt financing costs							867,000		$ 966,000
Interest expense							2,848,000	$ 4,235,000
2022 Notes | Convertible Notes
Debt Instrument [Line Items]
Face amount					$ 103,500,000	$ 225,000,000
Stated rate					4.95%	4.95%
Proceeds from debt, net of issuance costs					$ 100,749,000	$ 218,010,000
Redemption price rate									102.50%
Repayments of long-term debt									$ 50,554,000
Net realized (losses) on extinguishment of debt									(1,584,000)
Original debt		$ 3,000
Shares issued (in shares)		300
Converted instrument rate		100.2305%
Converted instrument rate amount per principal amount		$ 1,000
Outstanding amount							0		60,501,000
Repayments of convertible debt	$ 60,498,000
2022 Notes | Convertible Notes | Maximum
Debt Instrument [Line Items]
Repurchased face amount									60,000,000
2025 Notes | Convertible Notes
Debt Instrument [Line Items]
Face amount			$ 26,250,000	$ 175,000,000
Stated rate				6.375%
Proceeds from debt, net of issuance costs			$ 198,674,000
Outstanding amount							156,168,000		$ 156,168,000
Option to purchase term				13 days
Optional over-allotment amount				$ 26,250,000
2022 and 2025 Notes | Convertible Notes
Debt Instrument [Line Items]
Unamortized discount							3,369,000
Debt issuance costs, gross							$ 2,090,000