Equity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Beginning Balance	$ 1,337,650	$ 1,264,109	$ 1,374,704	$ 1,230,327
Net income	(6,229)	56,247	1,181	114,670	$ 114,670
Other comprehensive income (loss)	24,753	(799)	(5,529)	(15,039)
Dividend reinvestment	52	54	106	107
Capital stock issued under employee benefit and stock plans	5,903	5,149	8,287	11,146
Purchase of capital stock	(52)	(54)	(106)	(107)
Additions to noncontrolling interest	1,527		1,527
Cash dividends	(16,577)	(16,422)	(33,143)	(32,820)
Ending Balance	1,347,027	1,308,284	1,347,027	1,308,284
Capital stock [Member]
Beginning Balance	103,542	102,615	103,026	102,058
Dividend reinvestment	2	2	4	3
Capital stock issued under employee benefit and stock plans	76	85	592	642
Purchase of capital stock	(2)	(2)	(4)	(3)
Ending Balance	103,618	102,700	103,618	102,700
Additional paid-in capital [Member]
Beginning Balance	530,695	517,349	528,827	511,909
Dividend reinvestment	50	52	102	104
Capital stock issued under employee benefit and stock plans	5,827	5,064	7,695	10,504
Purchase of capital stock	(50)	(52)	(102)	(104)
Ending Balance	536,522	522,413	536,522	522,413
Retained earnings [Member]
Beginning Balance	1,066,763	940,983	1,076,862	900,683
Net income	(5,939)	54,698	528	111,396
Cash dividends	(16,577)	(16,422)	(33,143)	(32,820)
Ending Balance	1,044,247	979,259	1,044,247	979,259
Accumulated other comprehensive loss [Member]
Beginning Balance	(402,434)	(333,333)	(373,543)	(320,325)
Other comprehensive income (loss)	24,215	(1,299)	(4,676)	(14,307)
Ending Balance	(378,219)	(334,632)	(378,219)	(334,632)
Non-controlling interest [Member]
Beginning Balance	39,084	36,495	39,532	36,002
Net income	(290)	1,549	653	3,274
Other comprehensive income (loss)	538	500	(853)	(732)
Additions to noncontrolling interest	1,527		1,527
Cash dividends	0	0	0
Ending Balance	$ 40,859	$ 38,544	$ 40,859	$ 38,544