Summary of Significant Accounting Policies (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019	May 03, 2013 7.50% Convertible Senior Secured Notes due 2019
Notes payable
Fixed interest rate (as a percent)	7.50%		7.50%	7.50%
Revenue Recognition on Product Sales
Period for availability of requisite data for revenue recognition	56 days
Sales return period	12 months
Milestone revenues recorded	$ 0	$ 1.1
Advertising Expense
Advertising costs	$ 14.6	$ 5.8