Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Provision For Income Taxes Our income tax provision for interim periods is determined using an estimate of our annual effective tax rate, adjusted for discrete items, if any, that are taken into account in the relevant period. Each quarter we update our estimate of the annual effective tax rate, and if our estimated tax rate changes, we make a cumulative adjustment. Our interim income tax provision and our interim estimate of our annual effective tax rate are influenced by several factors, including foreign losses and capital gains and losses for which related deferred tax assets are offset by a valuation allowance, changes in tax laws and relative changes in unrecognized tax benefits. Additionally, our effective tax rate can be affected by the amount of pre-tax income or loss. For example, the impact of discrete items and non-deductible expenses on our effective tax rate is greater when our pre-tax income or loss is lower. Our income tax provision was $1 million for the three months ended June 30, 2019 compared to $18 million for the three months ended June 30, 2018. Our estimated effective income tax rate was (22.3)% and 18.6% for the three months ended June 30, 2019 and 2018, respectively. The variations in our effective tax rate from the U.S. federal statutory rate for the three months ended June 30, 2019 were primarily due to the change in net unrealized gains that are capital in nature and research and experimentation credits, partially offset by the impact of state and local taxes and the increase in our valuation allowance associated with certain foreign losses. For the year ended December 31, 2018, we recorded a tax provision of nil related to the tax on deemed mandatory repatriation of our unrepatriated foreign earnings. As a result of the release of new treasury regulations in June 2019, we have recorded additional tax expense of $2 million on deemed mandatory repatriation of certain deferred foreign earnings. The variations in our effective tax rate from the U.S. federal statutory rate for the three months ended June 30, 2018 were primarily due to the change in our valuation allowance associated with unrealized losses that are capital in nature. Our income tax provision was $9 million for the six months ended June 30, 2019 compared to $12 million for the six months ended June 30, 2018. Our estimated effective income tax rate was 47.8% and 18.0% for the six months ended June 30, 2019 and 2018, respectively. The variations in our effective tax rate from the U.S. federal statutory rate for the six months ended June 30, 2019 were primarily due to the change in net unrealized gains that are capital in nature and research and experimentation credits, partially offset by the impact of state and local taxes and the increase in our valuation allowance associated with certain foreign losses. For the year ended December 31, 2018, we recorded a tax provision of nil related to the tax on deemed mandatory repatriation of our unrepatriated foreign earnings. As a result of the release of new treasury regulations in June 2019, we have recorded additional tax expense of $2 million on deemed mandatory repatriation of certain deferred foreign earnings. The variations in our effective tax rate from the U.S. federal statutory rate for the six months ended June 30, 2018 were primarily due to research and experimentation credits, partially offset by the impact of state and local taxes, the increase in our valuation allowance associated with unrealized losses that are capital in nature, and the increase in our valuation allowance associated with certain foreign losses.