CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Activities:
Net income	$ 4,492	$ 2,757
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	3,601	3,729
Amortization of deferred financing costs	11	12
Deferred income taxes	85	9
Loss (gain) on sale of property, plant and equipment	28	(25)
Stock-based compensation	233	231
Changes in operating assets and liabilities:
Trade receivables, net	(4,735)	(2,224)
Inventories	1,696	438
Prepaid expenses and other current assets	(271)	(331)
Other assets	1	1
Accounts payable and accrued expenses	(1,374)	579
Other liabilities	30	214
Net cash provided by operating activities	3,797	5,390
Investing Activities:
Purchase of property, plant and equipment	(2,856)	(1,519)
Proceeds from sale of property, plant and equipment	97	42
Net cash used in investing activities	(2,759)	(1,477)
Financing Activities:
Repayments of term loans	(1,250)
Cash dividends paid	(697)
Purchase of treasury shares	(79)	(212)
Net cash used in financing activities	(2,026)	(212)
Net (decrease) increase in cash and cash equivalents	(988)	3,701
Cash and cash equivalents at beginning of period	49,475	29,787
Cash and cash equivalents at end of period	$ 48,487	$ 33,488