Balance Sheet Details (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accounts receivable:
Accounts receivable	$ 87,650	$ 88,045
Allowance for doubtful accounts	5,755	5,307
Inventories:
Finished goods	149,945	129,091
Work in process	1,077	1,132
Raw materials	4,505	4,369
Repair parts	10,140	9,778
Operating supplies	1,370	1,489
Total inventories, less allowances of $4,093 and $4,808	167,037	145,859
Inventory allowances	4,093	4,808
Prepaid and other current assets:
Value added tax	3,426	1,834
Prepaid expenses	3,784	4,653
Refundable, deferred and prepaid income taxes	0	3,107
Derivative asset	36	107
Total prepaid and other current assets	7,246	9,701
Other assets:
Deposits	763	733
Finance fees - net of amortization	14,329	9,427
Deferred taxes	585	567
Other assets	3,918	3,947
Total other assets	19,595	14,674
Accrued liabilities:
Accrued incentives	22,841	16,621
Workers compensation	8,125	8,484
Medical liabilities	3,853	3,607
Interest	3,510	13,008
Commissions payable	1,578	1,137
Contingency liability	2,719	2,719
Other accrued liabilities	7,766	8,351
Total accrued liabilities	50,392	53,927
Other long-term liabilities:
Deferred liability	5,147	4,070
Derivative liability	188	298
Other long-term liabilities	4,707	5,041
Total other long-term liabilities	10,042	9,409
Trade receivables [Member]
Accounts receivable:
Accounts receivable	86,266	86,523
Other receivables [Member]
Accounts receivable:
Accounts receivable	$ 1,384	$ 1,522