Income Taxes	9 Months Ended
Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rates for the three months ended September 30, 2017 and 2016 were (11)% and 35%, respectively. The effective tax rates for the nine months ended September 30, 2017 and 2016 were (5)% and 30%, respectively. The effective tax rates for the three and nine months ended September 30, 2017 differed from the Federal statutory rate primarily due to the recognition of excess tax benefits as a component of the provision for income taxes attributable to the adoption of ASU 2016-09 and Federal and California research and development ("R&D") credits, partially offset by state taxes, foreign taxes, and non-deductible expenses. The effective tax rates for the three and nine months ended September 30, 2016 differed from the Federal statutory rate primarily due to Federal and California R&D credits partially offset by state taxes, foreign taxes and non-deductible expenses. The decrease in effective tax rate for the three and nine months ended September 30, 2017 as compared to the same period in 2016 was due primarily to the recognition of excess tax benefits attributable to the adoption of ASU 2016-09 and an increase in foreign income taxed at rates lower than the US statutory rate. Gross unrecognized tax benefits were $37.2 million and $19.7 million as of September 30, 2017 and December 31, 2016, respectively. The gross unrecognized tax benefits, if recognized by the Company, will result in a reduction of approximately $33.3 million to the provision for income taxes thereby favorably impacting the Company’s effective tax rate. As of September 30, 2017, gross unrecognized tax benefits of $15.8 million was classified as “Other non-current liabilities” and $21.4 million as a reduction to deferred tax assets which was classified as "Other non-current assets" in the Consolidated Balance Sheets. The Company includes interest and penalties related to unrecognized tax benefits within the "Provision (benefit) for income taxes" on the Consolidated Statements of Operations and “Other non-current liabilities” in the Consolidated Balance Sheets. Interest and penalties included in the Company’s “Provision (benefit) for income taxes” were not material in any of the periods presented. Deferred tax assets of $374.0 million and $227.2 million were classified as “Other non-current assets” on the Consolidated Balance Sheets as of September 30, 2017 and December 31, 2016, respectively. In evaluating its ability to realize the net deferred tax assets, the Company considered all available positive and negative evidence, including its past operating results and the forecast of future market growth, forecasted earnings, future taxable income, and prudent and feasible tax planning strategies. As of September 30, 2017, the Company has a valuation allowance of $33.1 million primarily due to foreign tax credit carryovers. As of December 31, 2016, it was considered more likely than not that substantially all deferred tax assets would be realized. As a result of the adoption of ASU 2016-09 in the first quarter of 2017, the Company recorded a cumulative effect adjustment to increase retained earnings by $43.6 million with a corresponding increase to deferred tax assets for the Federal and state net operating losses attributable to excess tax benefits from stock-based compensation which had not been previously recognized. All excess tax benefits and deficiencies in the current and future periods will be recognized as income tax expense in the Company’s Consolidated Statement of Operations in the reporting period in which they occur. This will result in increased volatility in the Company’s effective tax rate. For the three and nine months ended September 30, 2017, the Company recognized a discrete tax benefit related to the excess tax benefits from stock-based compensation of $41.7 million and $110.5 million, respectively. The Company files U.S. Federal, state and foreign tax returns. The Company is currently under examination by the IRS for 2014 and 2015. The 2008 through 2015 state tax returns are subject to examination by state tax authorities. The Company has no significant foreign jurisdiction audits underway. The years 2011 through 2016 remain subject to examination by foreign tax authorities. Given the potential outcome of the current examinations as well as the impact of the current examinations on the potential expiration of the statute of limitations, it is reasonably possible that the balance of unrecognized tax benefits could significantly change within the next twelve months. At this time, an estimate of the range of reasonably possible adjustments to the balance of unrecognized tax benefits cannot be made.

Income Taxes

The effective tax rates for the three months ended September 30, 2017 and 2016 were (11)% and 35%, respectively. The effective tax rates for the nine months ended September 30, 2017 and 2016 were (5)% and 30%, respectively. The effective tax rates for the three and nine months ended September 30, 2017 differed from the Federal statutory rate primarily due to the recognition of excess tax benefits as a component of the provision for income taxes attributable to the adoption of ASU 2016-09 and Federal and California research and development ("R&D") credits, partially offset by state taxes, foreign taxes, and non-deductible expenses. The effective tax rates for the three and nine months ended September 30, 2016 differed from the Federal statutory rate primarily due to Federal and California R&D credits partially offset by state taxes, foreign taxes and non-deductible expenses. The decrease in effective tax rate for the three and nine months ended September 30, 2017 as compared to the same period in 2016 was due primarily to the recognition of excess tax benefits attributable to the adoption of ASU 2016-09 and an increase in foreign income taxed at rates lower than the US statutory rate.

Gross unrecognized tax benefits were $37.2 million and $19.7 million as of September 30, 2017 and December 31, 2016, respectively. The gross unrecognized tax benefits, if recognized by the Company, will result in a reduction of approximately $33.3 million to the provision for income taxes thereby favorably impacting the Company’s effective tax rate. As of September 30, 2017, gross unrecognized tax benefits of $15.8 million was classified as “Other non-current liabilities” and $21.4 million as a reduction to deferred tax assets which was classified as "Other non-current assets" in the Consolidated Balance Sheets. The Company includes interest and penalties related to unrecognized tax benefits within the "Provision (benefit) for income taxes" on the Consolidated Statements of Operations and “Other non-current liabilities” in the Consolidated Balance Sheets. Interest and penalties included in the Company’s “Provision (benefit) for income taxes” were not material in any of the periods presented.

Deferred tax assets of $374.0 million and $227.2 million were classified as “Other non-current assets” on the Consolidated Balance Sheets as of September 30, 2017 and December 31, 2016, respectively. In evaluating its ability to realize the net deferred tax assets, the Company considered all available positive and negative evidence, including its past operating results and the forecast of future market growth, forecasted earnings, future taxable income, and prudent and feasible tax planning strategies. As of September 30, 2017, the Company has a valuation allowance of $33.1 million primarily due to foreign tax credit carryovers. As of December 31, 2016, it was considered more likely than not that substantially all deferred tax assets would be realized.

As a result of the adoption of ASU 2016-09 in the first quarter of 2017, the Company recorded a cumulative effect adjustment to increase retained earnings by $43.6 million with a corresponding increase to deferred tax assets for the Federal and state net operating losses attributable to excess tax benefits from stock-based compensation which had not been previously recognized. All excess tax benefits and deficiencies in the current and future periods will be recognized as income tax expense in the Company’s Consolidated Statement of Operations in the reporting period in which they occur. This will result in increased volatility in the Company’s effective tax rate. For the three and nine months ended September 30, 2017, the Company recognized a discrete tax benefit related to the excess tax benefits from stock-based compensation of $41.7 million and $110.5 million, respectively.

The Company files U.S. Federal, state and foreign tax returns. The Company is currently under examination by the IRS for 2014 and 2015. The 2008 through 2015 state tax returns are subject to examination by state tax authorities. The Company has no significant foreign jurisdiction audits underway. The years 2011 through 2016 remain subject to examination by foreign tax authorities. Given the potential outcome of the current examinations as well as the impact of the current examinations on the potential expiration of the statute of limitations, it is reasonably possible that the balance of unrecognized tax benefits could significantly change within the next twelve months. At this time, an estimate of the range of reasonably possible adjustments to the balance of unrecognized tax benefits cannot be made.