Stockholders' Equity, Stock Options Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Summary of stock option activity under all stock plans
Underlying shares outstanding, Beginning balance	6,716
Underlying shares, granted	0
Underlying shares, exercised	(177)
Underlying shares, cancelled	(177)
Underlying shares outstanding, Ending balance	6,362
Underlying shares exercisable, Ending balance	6,040
Underlying shares vested or expected to vest, Ending balance	6,355
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted average exercise price outstanding, Beginning balance	$ 30.44
Weighted average exercise price, granted	$ 0.00
Weighted Average Exercise Price, exercised	$ 19.03
Weighted Average Exercise Price, cancelled	$ 30.91
Weighted Average Exercise Price outstanding, Ending balance	$ 30.75
Weighted Average Exercise Price option exercisable, Ending balance	$ 30.94
Weighted Average Exercise price vested or expected to vest, Ending balance	$ 30.75
Weighted Average Remaining Contractual Term outstanding, Ending balance	4 years 8 months 15 days
Weighted Average Remaining Contractual Term exercisable, Ending balance	4 years 7 months 2 days
Weighted Average Remaining Contractual Term vested or expected to vest, Ending balance	4 years 8 months 15 days
Aggregate Intrinsic Value outstanding, Ending balance	$ 24,996
Aggregate intrinsic value exercisable, Ending balance	23,264
Aggregate intrinsic value vested or expected to vest, Ending balance	$ 24,954