Income Taxes	9 Months Ended
Sep. 30, 2013
Income Tax Disclosure [Abstract]
Income Taxes	Note 7 — Income Taxes Forrester provides for income taxes on an interim basis according to management’s estimate of the effective tax rate expected to be applicable for the full fiscal year. Certain items such as changes in tax rates and tax benefits related to disqualifying dispositions of incentive stock options are treated as discrete items and are recorded in the period in which they arise. Income tax expense for the nine months ended September 30, 2013 was $7.1 million resulting in an effective tax rate of 39.5% for the period. Income tax expense for the nine months ended September 30, 2012 was $3.2 million resulting in an effective tax rate of 13.0% for the period. The increase in the effective tax rate during the nine months ended September 30, 2013 as compared to the prior year is primarily due to the 2012 period including a $5.5 million deferred tax benefit resulting from the settlement of a tax audit at one of the Company’s foreign subsidiaries. In addition, the 2012 period included a reduction in the reserve for uncertain tax positions as well as a credit due to a remeasurement gain of a euro-denominated deferred tax liability.

Income Taxes

9 Months Ended

Sep. 30, 2013

Note 7 — Income Taxes

Forrester provides for income taxes on an interim basis according to management’s estimate of the effective tax rate expected to be applicable for the full fiscal year. Certain items such as changes in tax rates and tax benefits related to disqualifying dispositions of incentive stock options are treated as discrete items and are recorded in the period in which they arise.

Income tax expense for the nine months ended September 30, 2013 was $7.1 million resulting in an effective tax rate of 39.5% for the period. Income tax expense for the nine months ended September 30, 2012 was $3.2 million resulting in an effective tax rate of 13.0% for the period. The increase in the effective tax rate during the nine months ended September 30, 2013 as compared to the prior year is primarily due to the 2012 period including a $5.5 million deferred tax benefit resulting from the settlement of a tax audit at one of the Company’s foreign subsidiaries. In addition, the 2012 period included a reduction in the reserve for uncertain tax positions as well as a credit due to a remeasurement gain of a euro-denominated deferred tax liability.