Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities
Net Income (loss)	$ (23,416)	$ 20,611	$ 32,420
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	13,709	12,892	13,055
Amortization	5,208	5,165	4,556
Impairment of long-lived assets	4,356	40	688
Insurance settlement	0	0	(1,539)
Non-cash restructuring charge	246	287	0
Deferred income taxes	(10,524)	(1,159)	11,349
Amortization of deferred financing fees	301	606	674
Loss on sale of equipment	23	137	28
Stock-based compensation expense	3,129	2,098	1,886
Tax benefit from stock options exercised	(244)	(293)	(1,109)
Changes in operating assets and liabilities, net of effects from acquisitions:
Trade accounts receivable	7,471	(349)	(5,293)
Inventories	2,769	(2,393)	2,039
Prepaid expenses and other current assets	1,234	(818)	(921)
Trade accounts payable, accrued expenses and other liabilities	(5,669)	(17,387)	4,254
Multiemployer pension plan withdrawal liability	29,837	(7,004)	(350)
Income taxes refundable (payable)	2,626	(2,926)	(12,727)
Net cash provided by operating activities	31,056	9,507	49,010
Cash flows from investing activities
Proceeds from sales of property and equipment	31	157	547
Proceeds from insurance settlement	0	0	1,539
Purchases of property and equipment	(19,764)	(24,721)	(12,205)
Acquisitions, net of cash acquired	2,449	(25,232)	(5,798)
Other	0	0	3
Net cash used in investing activities	(17,284)	(49,796)	(15,914)
Cash flows from financing activities
Issuance of common stock	2,374	1,216	5,513
Proceeds from issuance of long-term debt	220,965	220,868	99,062
Payments of long-term debt including current portion	(233,362)	(192,257)	(109,960)
Tax benefit from stock options exercised	244	293	1,109
Payment of deferred financing fees	(857)	(21)	(1,171)
Cash dividends	(8,252)	(8,199)	(5,079)
Purchase of common stock	0	(4,053)	0
Net cash (used in) provided by financing activities	(18,888)	17,847	(10,526)
Effect of foreign currency rate changes	1,035	(715)	2,152
Net (decrease) increase in cash and cash equivalents	(4,081)	(23,157)	24,722
Cash and cash equivalents beginning of period	13,732	36,889	12,167
Cash and cash equivalents end of period	9,651	13,732	36,889
Supplementary cash flow disclosures: [Abstract]
Dividends issued in the form of Class A common stock	54	51	36
Cash paid for interest	3,778	3,840	5,002
Cash paid (refunds received) for income taxes, net	$ (3,524)	$ 5,224	$ 11,651