CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating Activities:
Net income	$ 17,671	$ 14,871
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	10,378	9,861
Amortization of deferred financing costs	34	23
Deferred income taxes	3,489	2,518
Gain on disposition of property, plant and equipment	102	(6)
Stock-based compensation	623	498
Changes in operating assets and liabilities:
Trade receivables	(4,903)	(599)
Inventories	1,097	(1,291)
Prepaid expenses and other current assets	116	1,208
Other assets	9	(117)
Accounts payable and accrued expenses	101	433
Other liabilities	386	(113)
Net cash provided by operating activities	29,102	27,286
Investing Activities:
Purchase of property, plant and equipment	(7,075)	(7,129)
Proceeds from sale of property, plant and equipment	129	32
Net cash used in investing activities	(6,946)	(7,097)
Financing Activities:
Repayments of term loans	(3,750)	(3,750)
Purchase of treasury shares	(8,256)	(126)
Net cash used in financing activities	(12,006)	(3,876)
Net increase in cash and cash equivalents	10,151	16,313
Cash and cash equivalents at beginning of period	36,223	16,466
Cash and cash equivalents at end of period	$ 46,374	$ 32,779