Equity-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended	1 Months Ended					6 Months Ended					1 Months Ended
	Jun. 30, 2013 item	Feb. 28, 2013 Restricted stock units Senior management	Feb. 28, 2013 Restricted stock units Senior management Maximum	May 31, 2013 2007 Equity Incentive Plan	May 31, 2010 2007 Equity Incentive Plan	May 31, 2009 2007 Equity Incentive Plan	Jun. 30, 2013 2007 Equity Incentive Plan	Jun. 30, 2013 2007 Equity Incentive Plan Stock options Minimum	Jun. 30, 2013 2007 Equity Incentive Plan Stock options Maximum	Jun. 30, 2013 2000 Stock Plan	Jun. 30, 2013 2000 Stock Plan Restricted stock units	Jun. 30, 2013 Other Equity Compensation Grants Stock options Chief Development and Regulatory Affairs Officer	Jan. 31, 2013 Other Equity Compensation Grants Stock options Chief Commercial Officer	Jun. 30, 2013 Other Equity Compensation Grants Restricted stock units Chief Development and Regulatory Affairs Officer	Jan. 31, 2013 Other Equity Compensation Grants Restricted stock units Chief Commercial Officer
Equity-Based Compensation
Number of equity compensation plans	2
Equity compensation plans
Shares authorized for issuance				1,100,000	800,000	600,000
Number of options and restricted stock units granted (in shares)							6,142,775
Number of stock options expired or terminated (in shares)							2,466,736
Number of restricted stock units expired or terminated (in shares)							621,313
Stock options exercised (in shares)							56,524
Shares of common stock issued pursuant to vested restricted stock units							423,822
Number of stock options outstanding (in shares)							2,228,884			109,491
Number of restricted stock units outstanding (in shares)							345,496				0
Remaining number of shares available for future grants							2,075,954
Expiration term								7 years	10 years
Number of options granted (in shares)												60,000	75,000
Number of restricted stock units granted (in shares)		82,500												35,000	35,000
Award vesting period		3 years										4 years	4 years	4 years	4 years
Fair value of awards issued			$ 0.7
Expense recognition period		3 years