Income taxes	9 Months Ended
Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income taxes	Income taxes We recorded an income tax benefit for the three and nine months ended September 30, 2016 of $848 and $3,237, respectively, which primarily consisted of foreign income taxes. We recorded an income tax benefit for the three months ended September 30, 2015 of $2,161 and income tax expense of $12,205 for the nine months ended September 30, 2015 which primarily consisted of foreign and state income taxes. Our income tax benefit or expense is based on an annual effective tax rate forecast, including estimates and assumptions that could change during the year. The application of the requirements for accounting for income taxes in interim periods, after consideration of our valuation allowance, causes a significant variation in the typical relationship between income tax expense and pretax accounting income. As of September 30, 2016, all of Century's U.S. and certain foreign deferred tax assets, net of deferred tax liabilities, continue to be subject to a valuation allowance.

Income taxes

9 Months Ended

Sep. 30, 2016

We recorded an income tax benefit for the three and nine months ended September 30, 2016 of $848 and $3,237, respectively, which primarily consisted of foreign income taxes.

We recorded an income tax benefit for the three months ended September 30, 2015 of $2,161 and income tax expense of $12,205 for the nine months ended September 30, 2015 which primarily consisted of foreign and state income taxes.

Our income tax benefit or expense is based on an annual effective tax rate forecast, including estimates and assumptions that could change during the year. The application of the requirements for accounting for income taxes in interim periods, after consideration of our valuation allowance, causes a significant variation in the typical relationship between income tax expense and pretax accounting income.

As of September 30, 2016, all of Century's U.S. and certain foreign deferred tax assets, net of deferred tax liabilities, continue to be subject to a valuation allowance.