Income Taxes	9 Months Ended
Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes During the nine months ended September 30, 2019, the Company recorded an income tax benefit of $4,783, representing an effective tax rate of (19.8)%. The effective tax rate for the nine months ended September 30, 2019 was lower than the statutory tax rate of 21% principally due to excess stock deductions from the taxable compensation of share-based awards and federal and state research and development tax credits, partially offset by state and local income taxes. During the nine months ended September 30, 2018, the Company recorded an income tax benefit of $34,845, representing an effective tax rate of (194.9)%. The effective tax rate for the nine months ended September 30, 2018 was lower than the statutory tax rate of 21% principally due to the excess stock deductions from the taxable compensation of stock-based awards and federal and state research and development tax credits, partially offset by state and local income taxes. The Company and its subsidiaries are subject to various U.S. federal, state, and foreign income taxes. The Company is currently not subject to examination under the statute of limitations by the Internal Revenue Service and state jurisdictions for the tax years of 2014 and prior. The Company is currently open to examination in its foreign jurisdictions for tax years 2016 and after. In 2018, the Internal Revenue Service commenced a federal income tax audit with respect to the Company’s 2016 tax year, which was concluded in October 2019 for an immaterial amount. In 2019, the Internal Revenue Service commenced a federal employment tax audit with respect to the 2016, 2017 and 2018 calendar years.

Income Taxes

9 Months Ended

Sep. 30, 2019

11. Income Taxes

During the nine months ended September 30, 2019, the Company recorded an income tax benefit of $4,783, representing an effective tax rate of (19.8)%. The effective tax rate for the nine months ended September 30, 2019 was lower than the statutory tax rate of 21% principally due to excess stock deductions from the taxable compensation of share-based awards and federal and state research and development tax credits, partially offset by state and local income taxes.

During the nine months ended September 30, 2018, the Company recorded an income tax benefit of $34,845, representing an effective tax rate of (194.9)%. The effective tax rate for the nine months ended September 30, 2018 was lower than the statutory tax rate of 21% principally due to the excess stock deductions from the taxable compensation of stock-based awards and federal and state research and development tax credits, partially offset by state and local income taxes.

The Company and its subsidiaries are subject to various U.S. federal, state, and foreign income taxes. The Company is currently not subject to examination under the statute of limitations by the Internal Revenue Service and state jurisdictions for the tax years of 2014 and prior. The Company is currently open to examination in its foreign jurisdictions for tax years 2016 and after. In 2018, the Internal Revenue Service commenced a federal income tax audit with respect to the Company’s 2016 tax year, which was concluded in October 2019 for an immaterial amount. In 2019, the Internal Revenue Service commenced a federal employment tax audit with respect to the 2016, 2017 and 2018 calendar years.