Equity - Changes in equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Jul. 01, 2018	Jun. 30, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 6,102,792	$ 6,107,106	$ 5,968,152	$ 5,865,493
Impact of adoption of accounting standards						$ (251)
Net income	204,598	311,913	543,639	687,812
Other comprehensive income (loss)	184,999	(19,459)	113,304	(30,711)
Dividends paid	(113,672)	(99,589)	(227,025)	(200,458)
Stock incentive plan activity	7,529	21,195	38,176	49,281
Acquisition activity	6,255		6,255
Shares purchased at cost	(50,000)	(500,000)	(100,000)	(550,000)
Ending balance	$ 6,342,501	$ 5,821,166	$ 6,342,501	$ 5,821,166
Cash dividends per common share (in USD per share)	$ 0.88	$ 0.76	$ 1.76	$ 1.52
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	464,440	503,052	462,086	496,592
Stock incentive plan activity	(8,578)	18,802	(6,224)	25,262
Ending balance	455,862	521,854	455,862	521,854
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	13,003,084	11,902,300	12,777,538	11,625,975
Impact of adoption of accounting standards						1,483
Net income	204,474	311,737	543,372	687,448
Dividends paid	(113,306)	(99,589)	(226,658)	(200,458)
Ending balance	13,094,252	12,114,448	13,094,252	12,114,448
Accumulated Other Comprehensive (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(2,130,594)	(1,775,983)	(2,059,048)	(1,763,086)
Impact of adoption of accounting standards					$ (1,734)	$ (1,734)
Other comprehensive income (loss)	184,862	(19,514)	113,316	(30,677)
Ending balance	(1,945,732)	(1,795,497)	(1,945,732)	(1,795,497)
Treasury Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(5,330,837)	(4,618,512)	(5,309,130)	(4,590,138)
Stock incentive plan activity	16,107	2,393	44,400	24,019
Shares purchased at cost	(50,000)	(500,000)	(100,000)	(550,000)
Ending balance	(5,364,730)	(5,116,119)	(5,364,730)	(5,116,119)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	6,176	5,726	6,183	5,627
Net income	124	176	267	364
Other comprehensive income (loss)	137	55	(12)	(34)
Dividends paid	(366)		(367)
Acquisition activity	6,255		6,255
Ending balance	$ 12,326	$ 5,957	$ 12,326	$ 5,957