Income taxes	6 Months Ended
Jun. 30, 2018
Income taxes [Abstract]
Income taxes	9. Income taxes The estimated effective annual tax rate for the Company, which excludes discrete adjustments, was 25% and 31% for the six months ended June 30, 2018 and 2017, respectively. The decrease in the estimated effective annual tax rate is primarily due to the impact of the Tax Reform Act enacted on December 22, 2017 which reduced the U.S. federal corporate income tax rate from 35% to 21%, offset by state taxes, non-deductible expenses, international provisions from the U.S. tax reform and the impact of a change in the Company's jurisdictional mix of earnings. For the six months ended June 30, 2018 and 2017, the Company recorded a discrete tax benefit primarily associated with equity awards activity of $3.2 million and $1.1 million, respectively. On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. For the six months ended June 30, 2018, the Company did not change the provisional estimates recognized in 2017. Additional work is necessary for a more detailed analysis of the Company's deferred tax assets and liabilities and its historical foreign earnings as well as potential correlative adjustments. Any adjustment to these amounts will be recorded to current tax expense in the quarter of 2018 when the analysis is complete.

9. Income taxes

The estimated effective annual tax rate for the Company, which excludes discrete adjustments, was 25% and 31% for the six months ended June 30, 2018 and 2017, respectively. The decrease in the estimated effective annual tax rate is primarily due to the impact of the Tax Reform Act enacted on December 22, 2017 which reduced the U.S. federal corporate income tax rate from 35% to 21%, offset by state taxes, non-deductible expenses, international provisions from the U.S. tax reform and the impact of a change in the Company's jurisdictional mix of earnings. For the six months ended June 30, 2018 and 2017, the Company recorded a discrete tax benefit primarily associated with equity awards activity of $3.2 million and $1.1 million, respectively.

On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. For the six months ended June 30, 2018, the Company did not change the provisional estimates recognized in 2017. Additional work is necessary for a more detailed analysis of the Company's deferred tax assets and liabilities and its historical foreign earnings as well as potential correlative adjustments. Any adjustment to these amounts will be recorded to current tax expense in the quarter of 2018 when the analysis is complete.