Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income (loss)	$ 21,984	$ (38,118)	$ 44,450
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	23,680	28,070	24,572
Amortization of deferred financing fees	1,089	229	614
Deferred income taxes	(6,942)	(41,347)	(7,646)
Centennial long-lived asset impairment charge	0	105,119	0
Centennial goodwill impairment charge	0	0	3,973
(Gain) loss on sale of assets	(1,811)	(7,339)	(588)
Other	1,754	14,667	(14,572)
Working capital changes, excluding the effect of business acquisitions:
Accounts receivable	66,486	(22,506)	(2,779)
Inventories	24,149	(879)	(14,871)
Other current assets	4,530	201	(802)
Accounts payable	(28,867)	(2,963)	4,851
Other current liabilities	1,950	(15,335)	15,863
Net cash provided by operating activities	108,002	19,799	53,065
Investing Activities
Expenditures for property, plant and equipment	(10,615)	(57,500)	(57,449)
Acquisition of business	(413)	(25,000)	0
Proceeds from the sale of assets	3,471	8,134	2,504
Cash payment for cost method investment	0	0	(5,000)
Other	(734)	(568)	(789)
Net cash used for investing activities	(8,291)	(74,934)	(60,734)
Financing Activities
Reductions of long-term debt	(6,282)	(9,399)	(15,803)
Net additions (reductions) to revolving credit agreements	(71,635)	73,546	19,654
Cash dividends paid	(7,296)	(7,755)	(8,104)
Purchase of treasury shares	(24,010)	(35,075)	(31,306)
Financing fees paid	0	(333)	(1,209)
Other	922	(5)	(8)
Net cash provided by (used for) financing activities	(108,301)	20,979	(36,776)
Effect of exchange rate changes on cash	(46)	(99)	(20)
Decrease for the year	(8,636)	(34,255)	(44,465)
Balance at the beginning of the year	61,135	95,390	139,855
Balance at the end of the year	$ 52,499	$ 61,135	$ 95,390