Employee Stock and Benefit Plans (Common Stock and Preferred Stock) (Details) - $ / shares	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 03, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and RSUs outstanding under equity incentive plans	7,527,680	7,579,058	7,605,407	7,039,093
Total shares reserved for future issuance	9,540,243
Preferred Stock
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, par value per share (in dollars per share)	$ 0.001	$ 0.001
Preferred Stock
Preferred Stock
Preferred stock, shares authorized					20,000,000
Preferred stock, par value per share (in dollars per share)					$ 0.001
2000 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and RSUs outstanding under equity incentive plans	2,718,517
2012 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and RSUs outstanding under equity incentive plans	5,396,496
Shares available for future grants under an equity incentive plan	1,425,230