Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash	$ 16,760	$ 37,317
Accounts receivable, net	117,249	97,510
Inventories	85,629	91,469
Other current assets	18,370	16,503
Total current assets	238,008	242,799
Property, plant and equipment, net	264,805	278,442
Goodwill, net	83,004	83,941
Intangible asset, net	51,419	52,827
Investment in joint venture	36,895	34,703
Other non-current assets	20,255	20,001
Total assets	694,386	712,713
Current liabilities:
Accounts payable	61,801	71,094
Accrued salaries, wages and benefits	18,792	21,148
Current maturities of long-term debt	23,248	22,160
Income taxes payable	6,275	3,274
Current portion of obligations under capital lease	5,439	5,418
Other current liabilities	11,584	14,504
Total current liabilities	127,139	137,598
Non-current deferred tax liabilities	47,804	49,461
Long-term debt, net of current portion	334,995	328,026
Obligations under capital lease, net of current portion	12,823	14,539
Other non-current liabilities	10,337	9,390
Total liabilities	533,098	539,014
Total stockholders' equity	161,288	173,699
Total liabilities and stockholders' equity	$ 694,386	$ 712,713