Equity-Based Compensation (Details)	12 Months Ended		12 Months Ended		1 Months Ended		12 Months Ended	1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended				1 Months Ended
	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2012 Restricted stock units	Dec. 31, 2011 Restricted stock units	May 31, 2010 2007 Equity Incentive Plan	May 31, 2009 2007 Equity Incentive Plan	Dec. 31, 2012 2007 Equity Incentive Plan	May 31, 2009 2007 Equity Incentive Plan Stock options	Dec. 31, 2012 2007 Equity Incentive Plan Stock options Minimum	Dec. 31, 2012 2007 Equity Incentive Plan Stock options Maximum	May 31, 2009 2007 Equity Incentive Plan Restricted stock units	Dec. 31, 2012 2007 Equity Incentive Plan Restricted stock units Minimum	Dec. 31, 2012 2007 Equity Incentive Plan Restricted stock units Maximum	Dec. 31, 2012 2000 Stock Plan	Dec. 31, 2012 2000 Stock Plan Stock options	May 31, 2012 Other Equity Compensation Grants Stock options Chief Executive Officer item	May 31, 2012 Other Equity Compensation Grants Restricted stock units Chief Executive Officer item
Equity compensation plans
Shares authorized for issuance					800,000	600,000
Reduction in number of shares available for issuance								1			1.5
Award vesting period									3 years	4 years		3 years	4 years
Number of options and restricted stock units granted (in shares)							5,283,775							2,182,700		300,000	100,000
Number of stock options expired or terminated (in shares)	1,118,566						2,273,686							946,977
Number of restricted stock units expired or terminated (in shares)			371,201				615,430							1,500
Stock options exercised (in shares)	9,188						38,338							1,036,570
Shares of common stock issued pursuant to vested restricted stock units							347,725							42,500
Number of stock options outstanding (in shares)	2,190,073	1,817,027					1,734,920							155,153
Number of restricted stock units outstanding (in shares)			373,676	669,009			273,676
Remaining number of shares available for future grants							1,513,918
Expiration term									7 years	10 years					10 years
Number of installments in which awards will vest																4	4