Accumulated Other Comprehensive Income- Schedule of Balances of Each Component (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income
Balance at the beginning of the period	$ 239,670	$ 244,796
Other comprehensive income (loss) before reclassifications	(65)	114
Reclassification to (earnings) loss	(58)	(83)
Net current-period other comprehensive income (loss)	(123)	31
Balance at the end of the period	230,519	247,693
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income
Balance at the beginning of the period	1,980	2,137
Balance at the end of the period	1,857	2,168
Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income
Balance at the beginning of the period	0	32
Other comprehensive income (loss) before reclassifications	0	(18)
Reclassification to (earnings) loss	0	0
Net current-period other comprehensive income (loss)	0	(18)
Balance at the end of the period	0	14
Postemployment Benefits Net Actuarial Gain (Loss)
Accumulated Other Comprehensive Income
Balance at the beginning of the period	1,980	2,105
Other comprehensive income (loss) before reclassifications	196	132
Reclassification to (earnings) loss	(101)	(83)
Net current-period other comprehensive income (loss)	95	49
Balance at the end of the period	2,075	2,154
Interest Rate Swap Gain (Loss)
Accumulated Other Comprehensive Income
Balance at the beginning of the period	0	0
Other comprehensive income (loss) before reclassifications	(261)	0
Reclassification to (earnings) loss	43	0
Net current-period other comprehensive income (loss)	(218)	0
Balance at the end of the period	$ (218)	$ 0