Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
OPERATING ACTIVITIES:
Net income	$ 74,549	$ 45,429	$ 37,045
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	23,827	22,199	20,898
Amortization of deferred financing costs	17	2	6
Deferred income taxes	(923)	2,527	1,524
Loss (gain) on disposition of property, plant and equipment	363	(312)	10
Stock-based compensation	3,182	2,636	2,236
Changes in operating assets and liabilities:
Trade receivables, net	(4,460)	(6,438)	(3,736)
Inventories	(4,734)	(4,294)	94
Prepaid expenses and other current assets	(1,140)	(191)	(999)
Other assets	(142)	8	(41)
Accounts payable and accrued expenses	1,666	2,701	(1,101)
Other liabilities	54	96	(247)
Net cash provided by operating activities	92,259	64,363	55,689
INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(34,250)	(26,815)	(29,914)
Acquisition of a business, net of cash acquired		(5,630)
Proceeds from sale of property, plant and equipment	2,286	1,294	285
Net cash used in investing activities	(31,964)	(31,151)	(29,629)
FINANCING ACTIVITIES:
Cash dividends paid	(4,554)	(4,536)	(3,620)
Proceeds from exercise of stock options	113	120	84
Purchase of treasury shares	(1,274)	(767)	(731)
Net cash used in financing activities	(5,715)	(5,183)	(4,267)
Net increase in cash and cash equivalents	54,580	28,029	21,793
Cash and cash equivalents at beginning of period	133,384	105,355	83,562
Cash and cash equivalents at end of period	$ 187,964	$ 133,384	$ 105,355