Accounts Receivable, Trade (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accounts Receivable, Trade [Abstract]
Accounts receivable	$ 301,000	$ 396,870
Allowance for sales credits	(2,185)	(3,919)
Allowance for doubtful accounts	(272)	(624)
Total accounts receivable trade, net of allowances	$ 298,543	$ 392,327