|
Research and Development Collaboration and Licensing Agreements (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2012
|
|
| Research and Development Arrangement, Contract to Perform for Others [Line Items] | |||
| Useful life | 17 years | ||
| Contract to perform for others, gross costs incurred | $ 13.6 | $ 12.0 | $ 5.5 |