Contractual interest rate for funds borrowed, under the debt agreement.

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Debt - Redemption of 5.625% Senior Secured Notes (Detail) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Nov. 05, 2018	Oct. 09, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Apr. 30, 2019
Debt Instrument [Line Items]
Loss on extinguishment of debt			$ 0	$ 4,000	$ 0	$ 7,000
5.625% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate			5.625%	5.625%	5.625%	5.625%
5.625% Senior Secured Notes \| Acquisition Corp.
Debt Instrument [Line Items]
Interest rate	5.625%	5.625%					5.625%
Redemptions of senior notes	$ 26,550	$ 26,550
Senior notes redemption price	$ 27,380
Redemption price, percentage of principal amount redeemed	102.813%
Debt instrument remaining outstanding amount	$ 220,950
Loss on extinguishment of debt	$ 1,000			$ 4,000		$ 4,000