|6 Months Ended
Jun. 30, 2019
|Income Tax Disclosure [Abstract]
We recorded an income tax benefit of zero and $3 million during the three months ended June 30, 2019 and 2018, respectively, and an income tax provision of $3 million and $12 million during the six months ended June 30, 2019 and 2018, respectively. Changes in the income tax recorded between comparative periods are primarily attributable to changes in the income earned and tax transfer pricing applied to our U.K. integrated marketing function.
The effective tax rates during the three and six months ended June 30, 2019 and 2018 were lower than the 21% federal statutory rate during the 2019 and 2018 interim periods primarily as a result of maintaining a valuation allowance against our federal and state net deferred tax assets. Due to historical losses and other available evidence related to our ability to generate taxable income, we continue to maintain a valuation allowance against our federal and state net deferred tax assets at June 30, 2019.
The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef