Accounts Receivable (Impact Of Accounts Receivable Reserves And Allowance For Doubtful Accounts On The Gross Trade Accounts Receivable Balances) (Details) (USD $) In Thousands, unless otherwise specified					3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010	Mar. 31, 2012 Chargebacks [Member]	Dec. 31, 2011 Chargebacks [Member]	Mar. 31, 2012 Rebates And Incentive Programs [Member]	Dec. 31, 2011 Rebates And Incentive Programs [Member]	Mar. 31, 2012 Returns [Member]	Dec. 31, 2011 Returns [Member]	Mar. 31, 2012 Cash Discounts And Other [Member]	Dec. 31, 2011 Cash Discounts And Other [Member]
Accounts Receivable [Line Items]
Gross trade accounts receivable	$ 276,520	$ 269,204
Deductions from trade accounts receivable					(26,143)	(20,688)	(37,625)	(35,132)	(58,148)	(58,672)	(19,304)	(28,672)
Allowance for doubtful accounts	(100)	(100)		(1)
Accounts receivable, net	$ 135,200	$ 125,940