Income Taxes - Differences comprising the net deferred taxes shown on consolidated balance sheet (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Retirement benefits	$ 504,747	$ 368,269
Other liabilities and reserves	139,872	90,936
Long-term contracts	7,392	22,241
Stock-based compensation	35,483	38,730
Loss carryforwards	754,655	792,914
Unrealized currency exchange gains and losses	39,256	27,034
Inventory	5,242	5,540
Tax credit carryforwards	33,176	15,640
Undistributed foreign earnings	(15,196)	(16,762)
Depreciation and amortization	(988,886)	(589,454)
Valuation allowance	(771,430)	(797,692)
Net deferred tax (liability)	(255,689)	(42,604)
Change in net deferred tax (liability):
Provision for deferred tax	(13,692)	(32,537)	$ 41,412
Items of other comprehensive income	102,297	72,530
Acquisitions and other	(301,690)	94,638
Total change in net deferred tax	$ (213,085)	$ 134,631