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 Comprehensive Income [Abstract]
Net income	$ 34,525	$ 18,878	$ 105,973	$ 59,458
Other comprehensive income, net of tax:
Foreign currency translation adjustments	9,086	2,699	5,212	4,132
Net unrealized loss on cash flow hedges	(334)	(9,044)	(13,382)	(15,518)
Other comprehensive income, net of tax	8,752	(6,345)	(8,170)	(11,386)
Comprehensive income	$ 43,277	$ 12,533	$ 97,803	$ 48,072