Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Income Taxes [Line Items]
Deferred tax assets, product donations	$ 3,500,000
Excess tax benefits on exercise of nonqualified stock options	2,400,000	2,053,000	181,000
Expiry of product donation carryforwards	2014
Current unrecognized tax positions	14,409,000	31,571,000	30,023,000	30,217,000
Unrecognized tax benefits that would affect the effective tax rate, if recognized	9,800,000
Total amount of accrued interest and penalties resulting from unrecognized tax benefits	5,800,000	11,300,000
Recognized interest and penalties	400,000	600,000	700,000
Unrecognized tax position that may recognized within next twelve months	900,000
Number of jurisdictions where company is under audit	3
Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Net operating loss carry forwards for state income tax purposes	27,900,000
State [Member]
Income Taxes [Line Items]
Net operating loss carry forwards for state income tax purposes	$ 169,200,000