CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating Activities:
Net income	$ 10,609	$ 10,325
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	6,841	6,627
Amortization of deferred financing costs	22	13
Deferred income taxes	1,341	1,761
Gain on disposition of property, plant and equipment	10	(15)
Stock-based compensation	414	322
Changes in operating assets and liabilities:
Trade receivables	(4,310)	(5,395)
Inventories	908	132
Prepaid expenses and other current assets	508	1,068
Other assets	(21)	(118)
Accounts payable and accrued expenses	92	912
Other liabilities	53	(59)
Net cash provided by operating activities	16,467	15,573
Investing Activities:
Purchase of property, plant and equipment	(3,887)	(5,091)
Proceeds from sale of property, plant and equipment	83	26
Net cash used in investing activities	(3,804)	(5,065)
Financing Activities:
Repayments of term loans	(2,500)	(2,500)
Purchase of treasury shares	(126)	(126)
Net cash used in financing activities	(2,626)	(2,626)
Net increase in cash and cash equivalents	10,037	7,882
Cash and cash equivalents at beginning of period	36,223	16,466
Cash and cash equivalents at end of period	$ 46,260	$ 24,348