Stock-Based Compensation (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Performance-contingent
Number of shares outstanding subject to RSUs and vesting or performance conditions with vesting
Balance at the beginning of the period (in shares)	2,365,000
Granted (in shares)	684,000
Released RSUs and RSAs (in shares)	(823,000)
Forfeited (in shares)	(454,000)
Balance at the end of the period (in shares)	1,772,000
Weighted-average fair value per share at grant
Balance at the beginning of the period (in dollars per share)	$ 23.66
Granted (in dollars per share)	$ 23.36
Released RSUs and RSAs (in dollars per share)	$ 23.20
Forfeited (in dollars per share)	$ 15.73
Balance at the end of the period (in dollars per share)	$ 25.78
Stock options
Number of Shares Subject to Outstanding Options
Balance at the beginning of the period (in shares)	4,824,000
Granted (in shares)	885,000
Exercised (in shares)	(1,177,000)
Forfeited (in shares)	(393,000)
Anti-dilution adjustments (in shares)	1,283,000
Balance at the end of the period (in shares)	5,422,000	4,824,000
Weighted-average exercise price of outstanding options
Balance at the beginning of the period (in dollars per share)	$ 25.30
Granted (in dollars per share)	$ 30.42
Exercised (in dollars per share)	$ 14.01
Forfeited (in dollars per share)	$ 27.26
Balance at the end of the period (in dollars per share)	$ 22.46	$ 25.30
Additional disclosures
Aggregate intrinsic value of options outstanding	$ 700,000
Aggregate intrinsic value of options exercisable	700,000
Total intrinsic value of options exercised	17,500,000	41,400,000	15,200,000
Total estimated fair value of options vested	5,700,000	3,700,000	4,100,000
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)	1.60%	0.80%	0.70%
Risk-free interest rate, maximum (as a percent)	2.10%	2.00%	1.20%
Volatility, minimum (as a percent)	52.00%	58.00%	55.00%
Volatility, maximum (as a percent)	60.00%	60.00%	60.00%
Dividend yield (as a percent)		0.00%	0.00%
Weighted-average estimated fair value of awards granted (in dollars per share)	$ 15.63	$ 19.96	$ 11.50
Stock options | Minimum
Weighted-average assumptions
Expected life (in years)	5 years	5 years	5 years
Dividend yield (as a percent)	3.00%
Stock options | Maximum
Weighted-average assumptions
Expected life (in years)	6 years	6 years	6 years
Dividend yield (as a percent)	4.00%
RSUs
Number of shares outstanding subject to RSUs and vesting or performance conditions with vesting
Balance at the beginning of the period (in shares)	1,115,000
Granted (in shares)	157,000
Released RSUs and RSAs (in shares)	(538,000)
Forfeited (in shares)	(155,000)
Anti-dilution adjustments (in shares)	$ 196,000
Balance at the end of the period (in shares)	775,000
Weighted-average fair value per share at grant
Balance at the beginning of the period (in dollars per share)	$ 21.53
Granted (in dollars per share)	$ 23.08
Released RSUs and RSAs (in dollars per share)	$ 18.35
Forfeited (in dollars per share)	$ 22.00
Balance at the end of the period (in dollars per share)	$ 18.53
Employee Stock Purchase Plan
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)	0.10%	0.10%	0.10%
Risk-free interest rate, maximum (as a percent)	0.50%	0.30%	0.30%
Volatility, minimum (as a percent)	43.00%	56.00%	51.00%
Volatility, maximum (as a percent)	55.00%	61.00%	64.00%
Dividend yield (as a percent)	8.00%	0.00%	0.00%
Weighted-average estimated fair value of awards granted (in dollars per share)	$ 4.49	$ 16.44	$ 8.07
Employee Stock Purchase Plan | Minimum
Weighted-average assumptions
Expected life (in years)	6 months	6 months	6 months
Employee Stock Purchase Plan | Maximum
Weighted-average assumptions
Expected life (in years)	2 years	2 years	2 years