Employee Stock Purchase Plan Stock Options and Warrants Schedule of Employee Service-based Compensation, Allocation of Recognized Period Costs, by Report Line (Details) (USD $)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Cost of Goods Sold	$ 193,981,000	$ 168,257,000	$ 148,660,000
Research and Development Expense	21,938,000	15,335,000	11,168,000
Selling, General and Administrative Expense	104,502,000	87,615,000	64,787,000
Allocated Share-based Compensation Expense	1,644,000	1,294,000	1,182,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	5,900,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	3.6
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Cost of Goods Sold	241,000	201,000	205,000
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Research and Development Expense	86,000	56,000	57,000
Selling General And Administrative Stock Based Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Selling, General and Administrative Expense	$ 1,317,000	$ 1,037,000	$ 920,000

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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- Definition

The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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