Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net earnings	$ 188,928	$ 33,937	$ 136,791
Other comprehensive income (loss), net of income taxes
Pension and other postretirement benefit plans activity	5,327	(12,752)	(2,591)
Unrealized gain (loss) on interest rate swaps	4,165	(3,101)	(1,299)
Other comprehensive income (loss), net of income taxes	9,492	(15,853)	(3,890)
Comprehensive income	$ 198,420	$ 18,084	$ 132,901