Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (6,725)	$ 30,987	$ (152,775)	$ (37,992)
Other comprehensive income (loss):
Foreign currency translation adjustment	2,851	1,542	(2,317)	(848)
Unrealized gain (loss) due to change in fair value of derivatives, net of tax	(1,282)		(14,639)
Total other comprehensive income (loss)	1,569	1,542	(16,956)	(848)
Comprehensive income (loss)	$ (5,156)	$ 32,529	$ (169,731)	$ (38,840)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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