Equity Incentive Plans and Stock-Based Compensation (Details 2) - $ / shares				1 Months Ended		3 Months Ended	12 Months Ended
		Apr. 23, 2015	Apr. 24, 2014	Apr. 30, 2012	Apr. 30, 2009	Jun. 30, 2012	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Shares available for grant
Increase in shares approved for issuance					6,500,000	6,500,000
Potential Additional Performance Stock Units [Domain]
Shares available for grant
Nonvested equity stock and stock units granted (in shares)							238,980
Stock Compensation Plan [Member]
Shares available for grant
Increase in shares approved for issuance			10,000,000
Shares available, at the end of the period							11,173,545.000
Options
Shares available for grant
Stock options granted (in shares)							(362,335)		(2,370,313)	(2,084,276)
Stock options forfeited (in shares)							1,624,823		1,400,349	3,318,022
Options granted (in dollars per share)							$ 11.27		$ 9.63	$ 6.09
Expected weighted-average period for recognition of compensation cost (in years)							1 year 9 months
Employee Stock [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized		2,000,000	1,500,000	1,500,000
Shares available for grant
Shares available, at the end of the period							2,000,000
Expected weighted-average period for recognition of compensation cost (in years)							4 months
Stock Compensation Plan [Member]
Shares available for grant
Shares available, at the beginning of the year							10,724,228		2,527,428	2,729,159
Increase in shares approved for issuance							4,000,000		10,000,000
Stock options granted (in shares)							(362,335)		(2,370,313)	(2,084,276)
Stock options forfeited (in shares)							1,624,823		1,400,349	3,318,022
Stock options expired under former plans (in shares)							(657,878)		(373,043)	(1,157,419)
Nonvested equity stock and stock units granted (in shares)	[2]						(4,537,797)	[1]	(585,753)	(709,611)
Nonvested equity stock and stock units forfeited (in shares)	[2]						382,504		125,560	431,553
Shares available, at the end of the period							11,173,545		10,724,228	2,527,428
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

[1] Amount includes 238,980 shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled "Nonvested Equity Stock and Stock Units" below.

[2] For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each restricted stock granted reduces the number of shares available for grant by 1.5 shares and each restricted stock forfeited increases shares available for grant by 1.5 shares.