Significant Accounting Policies Sales Allowances and Accruals (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2008
Cash Discounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Sales Allowances and Accurals, Beginning of Period	$ 1,849	$ 1,119		$ 664
Allowance for Sales, Current Period	12,240	10,911	9,817
Allowance for Sales, Prior Period	0	0	0
Actual Sales Credits, Prior Period	(1,849)	(1,119)	(688)
Actual Sales Credits, Current Period	(10,230)	(9,062)	(8,674)
Sales Allowances and Accurals, End of Period	2,010	1,849	1,119	664
Returns [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Sales Allowances and Accurals, Beginning of Period	3,871	627		3,764
Allowance for Sales, Current Period	854	3,807	3,420
Allowance for Sales, Prior Period	0	0	1,163
Actual Sales Credits, Prior Period	(3,612)	(556)	(3,811)
Actual Sales Credits, Current Period	0	(7)	(3,909)
Sales Allowances and Accurals, End of Period	1,113	3,871	627	3,764
Chargebacks [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Sales Allowances and Accurals, Beginning of Period	15,640	13,863		4,664
Allowance for Sales, Current Period	68,179	60,318	53,756
Allowance for Sales, Prior Period	0	0	0
Actual Sales Credits, Prior Period	(9,673)	(8,481)	(4,041)
Actual Sales Credits, Current Period	(59,303)	(50,060)	(40,516)
Sales Allowances and Accurals, End of Period	14,843	15,640	13,863	4,664
Rebates [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Sales Allowances and Accurals, Beginning of Period	1,170	11		11
Allowance for Sales, Current Period	0	1,159	0
Allowance for Sales, Prior Period	0	0	0
Actual Sales Credits, Prior Period	(1,170)	0	0
Actual Sales Credits, Current Period	0	0	0
Sales Allowances and Accurals, End of Period	0	1,170	11	11
Fees-for-Service [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Sales Allowances and Accurals, Beginning of Period	3,269	2,634		3,125
Allowance for Sales, Current Period	9,914	9,136	10,976
Allowance for Sales, Prior Period	0	0	0
Actual Sales Credits, Prior Period	(2,885)	(2,294)	(3,051)
Actual Sales Credits, Current Period	(6,721)	(6,207)	(8,416)
Sales Allowances and Accurals, End of Period	$ 3,577	$ 3,269	$ 2,634	$ 3,125