Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 15,480	$ 17,765
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation	5,398	6,038
Deferred income taxes	(124)	953
Stock-based compensation expense	909	1,364
Excess tax benefit from stock-based payment arrangements		(1,401)
Provision for losses on accounts receivable	(110)
Gain on disposition of capital assets	(1,794)	(147)
Changes in operating assets and liabilities:
Trade receivables	(2,820)	974
Inventories	(6,799)	(6,794)
Other current assets	(547)	(712)
Other assets	14	464
Accounts payable - trade	(420)	3,882
Accrued liabilities	4,915	1,856
Other long-term liabilities	187	(554)
Net cash provided by operating activities	14,289	23,688
INVESTING ACTIVITIES:
Purchases of investments	(30,196)	(12,580)
Proceeds from sales of investments	30,129	2,485
Proceeds from sale of capital assets	6,152	147
Capital expenditures	(20,149)	(9,764)
Net cash (used in) provided by investing activities	(14,064)	(19,712)
FINANCING ACTIVITIES:
Dividends paid	(5,018)	(4,499)
Proceeds from issuance of common stock	77	1,071
Shares withheld for employee tax obligations	(552)	(1,131)
Excess Tax Benefit from Share-based Compensation, Financing Activities		(1,401)
Net cash used in financing activities	(5,493)	(3,158)
Increase (decrease) in cash and cash equivalents	(5,268)	818
Cash and cash equivalents at beginning of year	28,874	36,780
Cash and cash equivalents at end of year	23,606	37,598
SUPPLEMENTAL INFORMATION CASH PAID DURING THE PERIOD FOR:
Income taxes paid (refunded)	5,190	5,795
Capital Expenditures Incurred but Not yet Paid	$ 2,770	$ 1,133