Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (4,529)	$ 9,451	$ 19	$ 31,874
Available-for-sale securities
Available-for-sale securities, Pre-tax	(4)	3	(42)	(17)
Available-for-sale securities, Tax	1	(1)	11	4
Available-for-sale securities, Net of Tax	(3)	2	(31)	(13)
Postemployment severance actuarial change
Postemployment severance actuarial change, Pre-tax	174	120	476	565
Postemployment severance actuarial change, Tax	(45)	(31)	(123)	(146)
Postemployment severance actuarial change, Net of Tax	129	89	353	419
Amortization of actuarial change
Amortization of actuarial change, Pre-tax	(112)	(82)	(333)	(260)
Amortization of actuarial change, Tax	29	21	86	67
Amortization of actuarial change, Net of Tax	(83)	(61)	(247)	(193)
Other comprehensive income (loss)
Other comprehensive income (loss), Pre-tax	58	41	101	288
Other comprehensive income (loss), Tax	(15)	(11)	(26)	(75)
Other comprehensive income (loss), Net of Tax	43	30	75	213
Total comprehensive income (loss)	$ (4,486)	$ 9,481	$ 94	$ 32,087