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Amount of interest expense on finance lease liability.

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Amount of amortization expense attributable to right-of-use asset from finance lease.

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Amount of lease cost recognized by lessee for lease contract.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Amount of short-term lease cost, excluding expense for lease with term of one month or less.

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Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

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Leases - Components of lease expenses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Oct. 01, 2019	Sep. 30, 2019
New Accounting Pronouncements and Changes in Accounting
Retained earnings	$ 451,364	$ 451,364		$ 599,548
Components of lease expenses
Operating lease cost	48,800	95,400
Finance lease cost
Amortization of right-of-use assets	5,100	9,700
Interest on lease liabilities	500	1,000
Variable lease cost	8,800	18,300
Short-term lease cost	2,400	5,800
Total lease cost	$ 65,600	$ 130,200
Accounting Standards Update 2016-02
New Accounting Pronouncements and Changes in Accounting
Retained earnings			$ (87,800)