Derivative Instruments - Summary of the (Loss) Gain Recognized in Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (loss) recognized in Other comprehensive (loss) income	$ 26,920	$ 19,884	$ 32,236	$ 23,593
Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (loss) recognized in Other comprehensive (loss) income	25,839	17,219	28,719	18,348
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swap contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (loss) recognized in Other comprehensive (loss) income	25,839	17,246	28,719	18,465
Cash Flow Hedging | Designated as Hedging Instrument | Foreign currency forward contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (loss) recognized in Other comprehensive (loss) income	$ 0	$ (27)	$ 0	$ (117)