Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 89,679	$ 109,262	$ 135,768	$ 132,777
Other comprehensive income (loss), net of tax:
Hedge gain arising during the period, net of tax of $1.2 million and $0 million in the second quarter of 2022 and 2021, respectively, and $2 million and $0 million in the first six months of 2022 and 2021, respectively	3,697	7,017	6,192	238
Foreign currency translation adjustment, net of tax of $0 for each period	(11,356)	(15,851)	(17,024)	4,124
Unrealized loss on marketable securities, net of tax of $0 for each period	0	0	0	(307)
Amortization of net actuarial pension loss included in net income, net of tax of $0.1 million and $0.3 million in the second quarter of 2022 and 2021, respectively, and $0.2 million and $0.6 million in the first six months of 2022 and 2021, respectively	260	744	525	1,476
Change in unamortized pension gain (loss) during the period related to changes in foreign currency	538	1,018	923	(94)
Other comprehensive income (loss)	(6,861)	(7,072)	(9,384)	5,437
Comprehensive income	$ 82,818	$ 102,190	$ 126,384	$ 138,214