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Balance Sheet Information - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Sep. 30, 2021	Jul. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Feb. 28, 2021
Condensed Balance Sheet Statements Captions [Line Items]
Depreciation expense			$ 81,200	$ 80,800	$ 76,200
Estimated initial equity warrant asset value						$ 16,400
Warrant asset value	$ 16,400		16,400
Losses on investments			(6,816)
Amortization of unfavorable lease liability					5,718
Write off of unfavorable lease liability					$ 800
Archer Aviation, Inc. [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Losses on investments			$ (6,800)
Heart Aerospace Incorporated [Member] | Forward Purchase Contract [Member] | Preferred Stock [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Purchase of preferred stock		$ 5,000
Initial investment in preferred stock measured at cost		$ 5,000
Class A [Member] | Archer Aviation, Inc. [Member]
Condensed Balance Sheet Statements Captions [Line Items]
Stock issued during period, Shares	500,000
Stock issued during period, Value	$ 5,000
Total grant date value, Additional warrant to purchase shares	$ 5,600

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