Equity-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended	1 Months Ended					9 Months Ended					1 Months Ended	9 Months Ended		1 Months Ended	9 Months Ended
	Sep. 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	Sep. 30, 2013 2007 Equity Incentive Plan	Sep. 30, 2013 2007 Equity Incentive Plan Stock options Minimum	Sep. 30, 2013 2007 Equity Incentive Plan Stock options Maximum	Sep. 30, 2013 2000 Stock Plan	Sep. 30, 2013 2000 Stock Plan Restricted stock units	Feb. 28, 2013 Other Equity Compensation Grants Stock options Senior management	Sep. 30, 2013 Other Equity Compensation Grants Stock options Senior management	Sep. 30, 2012 Other Equity Compensation Grants Stock options Senior management	Feb. 28, 2013 Other Equity Compensation Grants Restricted stock units Senior management	Sep. 30, 2013 Other Equity Compensation Grants Restricted stock units Senior management	Sep. 30, 2012 Other Equity Compensation Grants Restricted stock units Senior management
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)							6,220,350
Number of stock options expired or terminated (in shares)							2,532,981
Number of restricted stock units forfeited (in shares)							626,122									15,000
Stock options exercised (in shares)							137,865
Shares of common stock issued pursuant to vested restricted stock units							423,997
Number of stock options outstanding (in shares)							2,157,148			104,941
Number of restricted stock units outstanding (in shares)							342,237				0
Remaining number of shares available for future grants							2,074,125			0
Expiration term								7 years	10 years
Number of options granted (in shares)													210,000	300,000
Number of options forfeited (in shares)													45,000
Number of restricted stock units granted (in shares)		82,500														95,000	100,000
Award vesting period		3 years										4 years			4 years
Fair value of awards issued			$ 0.7
Expense recognition period		3 years