Equity Incentive Plans and Stock-Based Compensation (Details 2) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		12 Months Ended			0 Months Ended	12 Months Ended
	Apr. 30, 2009	Jun. 30, 2012	Dec. 31, 2012 Employee Stock Option	Dec. 31, 2013 Employee Stock Option	Dec. 31, 2012 Employee Stock Option	Dec. 31, 2011 Employee Stock Option	Jun. 22, 2012 Stock Option Exchange Program Employee Stock Option	Dec. 31, 2012 Stock Option Exchange Program Employee Stock Option	Dec. 31, 2013 Stock-Based Incentive Compensation Plans	Dec. 31, 2012 Stock-Based Incentive Compensation Plans	Dec. 31, 2011 Stock-Based Incentive Compensation Plans
Shares available for grant
Shares available, at the beginning of the year									2,729,159	2,812,876	5,348,162
Increase in shares approved for issuance	6,500,000	6,500,000								6,500,000
Stock options granted (in shares)				(2,084,276)	(7,789,220)	(2,357,001)		(2,840,986)	(2,084,276)	(7,789,220)	(2,357,001)
Stock options forfeited (in shares)				3,318,022	2,610,812	865,097			3,318,022	2,610,812	865,097
Stock options expired under former plans (in shares)									(1,157,419)	(576,763)	(503,526)
Nonvested equity stock and stock units granted (in shares)									(709,611)	(1,113,014)	(562,257)
Nonvested equity stock and stock units forfeited (in shares)									431,553	284,468	22,401
Shares available, at the end of the period									2,527,428	2,729,159	2,812,876
Conversion factor used to calculate the decrease in the number of shares available for grant resulting from the grant of restricted stock awards									1.5
Conversion factor used to calculate the increase in the number of shares available for grant resulting from the forfeiture of restricted stock awards									1.5
Minimum contractual term of options granted in stock option exchange program (in years)							5 years
Vesting period								3 years
Incremental compensation cost of new options granted								$ 1.0
Unrecognized compensation cost of original options							$ 19.9
Options granted (in dollars per share)				$ 6.09	$ 5.81	$ 18.83	$ 5.63
Options surrendered in stock option exchange program			6,449,255					6,449,255
Expected weighted-average period for recognition of compensation cost (in years)				2 years 3 months 1 day				3 years