Income taxes	3 Months Ended
Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income taxes	Income taxes We recorded an income tax benefit for the three months ended March 31, 2017 and 2016 of $308 and $2,070, respectively, which primarily consisted of foreign 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 March 31, 2017, 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

3 Months Ended

Mar. 31, 2017

We recorded an income tax benefit for the three months ended March 31, 2017 and 2016 of $308 and $2,070, respectively, which primarily consisted of foreign 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 March 31, 2017, 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.