Equity - Changes in equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 6,107,106	$ 5,530,659	$ 5,865,493	$ 5,267,346
Impact of adoption of accounting standards					$ (251)
Net income	311,913	56,322	687,812	341,857
Other comprehensive income (loss)	(19,459)	56,702	(30,711)	156,316
Dividends paid	(99,589)	(88,083)	(200,458)	(176,187)
Stock incentive plan activity	21,195	13,610	49,281	29,907
Acquisition activity				(29)
Shares purchased at cost	(500,000)	(50,000)	(550,000)	(100,000)
Ending balance	$ 5,821,166	$ 5,519,210	$ 5,821,166	$ 5,519,210
Cash dividends per common share (in USD per share)	$ 0.76	$ 0.66	$ 1.52	$ 1.32
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 90,523	$ 90,523	$ 90,523	$ 90,523
Ending balance	90,523	90,523	90,523	90,523
Additional Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	503,052	528,956	496,592	543,879
Stock incentive plan activity	18,802	5,047	25,262	(9,876)
Ending balance	521,854	534,003	521,854	534,003
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	11,902,300	11,127,641	11,625,975	10,930,348
Impact of adoption of accounting standards					1,483
Net income	311,737	56,159	687,448	341,556
Dividends paid	(99,589)	(88,083)	(200,458)	(176,187)
Ending balance	12,114,448	11,095,717	12,114,448	11,095,717
Accumulated Other Comprehensive (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,775,983)	(1,824,503)	(1,763,086)	(1,924,204)
Impact of adoption of accounting standards					$ (1,734)
Other comprehensive income (loss)	(19,514)	56,775	(30,677)	156,476
Ending balance	(1,795,497)	(1,767,728)	(1,795,497)	(1,767,728)
Treasury Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(4,618,512)	(4,397,677)	(4,590,138)	(4,378,897)
Stock incentive plan activity	2,393	8,563	24,019	39,783
Shares purchased at cost	(500,000)	(50,000)	(550,000)	(100,000)
Ending balance	(5,116,119)	(4,439,114)	(5,116,119)	(4,439,114)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	5,726	5,719	5,627	5,697
Net income	176	163	364	301
Other comprehensive income (loss)	55	(73)	(34)	(160)
Acquisition activity				(29)
Ending balance	$ 5,957	$ 5,809	$ 5,957	$ 5,809