Derivative Instruments - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets, notional	$ 1,232,056
Derivative asset	11,989
Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets, notional	1,100,000
Derivative asset	4,874
Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets, notional	132,056		$ 145,181
Derivative asset	7,115		13,967
Interest rate swap contracts | Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives entered into	900,000	$ 300,000
Derivative assets, notional	1,200,000
Interest rate swap contracts | Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets, notional	132,056		145,181
Derivative asset	5,226		12,053
Equity warrants | Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets, notional	0		0
Derivative asset	$ 1,889		$ 1,914