CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 142,795	$ 42,420	$ 184,841	$ 79,083
Other comprehensive income:
Foreign currency translation adjustment	1,191	(6,424)	5,554	(10,126)
Change in fair value of interest rate swap agreements, net of tax	2,613	10,045	3,121	12,899
Other comprehensive income, net of tax	3,804	3,621	8,675	2,773
Comprehensive income	$ 146,599	$ 46,041	$ 193,516	$ 81,856