Summary of Significant Accounting Policies (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012 statement plan	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Number of stock-based compensation plans	5
Recent accounting changes and Pronouncements
Number of separate but consecutive statements	2
Stock-Based Compensation
Stock-based compensation expense	$ 16.4	$ 15.0	$ 9.2
Research and Development
Research and development costs	87.7	80.6	72.2
Restricted Stock
Stock-Based Compensation
Stock-based compensation expense	4.5	4.0	2.6
Stock Options
Stock-Based Compensation
Stock-based compensation expense	6.7	6.9	6.6
Performance shares
Stock-Based Compensation
Stock-based compensation expense	$ 5.2	$ 4.1

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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