ARCALYST (rilonacept) Product Revenue (Policies)

9 Months Ended

Sep. 30, 2011

Product Revenue [Abstract]

Revenue recognition, deferred revenue

The Company had limited historical return experience for ARCALYST® beginning with initial sales in 2008 through the end of 2009; therefore, ARCALYST® net product sales were deferred until the right of return no longer existed and rebates could be reasonably estimated.  Effective in the first quarter of 2010, the Company determined that it had accumulated sufficient historical data to reasonably estimate both product returns and rebates of ARCALYST®.