CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 321,480	$ 265,604	$ 301,171
Other comprehensive income (loss):
Foreign currency translation adjustment	(4,990)	(6,103)	1,986
Effects of post-retirement adjustments, net of tax	141	(109)	627
Change in fair value of interest rate swap agreements, net of tax	(24,280)	(17,914)	7,473
Other comprehensive income (loss), net of tax	(29,129)	(24,126)	10,086
Comprehensive income	$ 292,351	$ 241,478	$ 311,257