Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income taxes The provision for income taxes for the first three months of 2018 reflects an estimated annual tax rate of 24 percent, compared to 32 percent for the first three months of 2017, excluding the discrete items discussed in the following paragraph. The decrease is primarily due to the reduction in the U.S. corporate tax rate beginning January 1, 2018, along with other changes in the geographic mix of profits from a tax perspective. In addition, a discrete tax benefit of $40 million was recorded in the first three months of 2018, compared to $17 million in the first three months of 2017, for the settlement of stock-based compensation awards with associated tax deductions in excess of cumulative U.S. GAAP compensation expense. The provision for income taxes in the first three months of 2017 also included a $15 million increase to prior year taxes related to non-U.S. restructuring costs. Our analysis of U.S. tax reform legislation, updated through March 31, 2018, resulted in no change to the 2017 year-end provisional charge of $2.371 billion. We will continue to update our calculations as additional required information is prepared and analyzed, interpretations and assumptions are refined, additional guidance is issued, and due to actions we may take as a result of the legislation. These updates could significantly impact the provision for income taxes, the amount of taxes payable and the deferred tax asset and liability balances. On January 31, 2018, we received a Revenue Agent's Report from the Internal Revenue Service (IRS) indicating the end of the field examination of our U.S. income tax returns for 2010 to 2012. In the audits of 2007 to 2012 including the impact of a loss carryback to 2005, the IRS has proposed to tax in the United States profits earned from certain parts transactions by Caterpillar SARL, based on the IRS examination team's application of the "substance-over-form" or "assignment-of-income" judicial doctrines. We are vigorously contesting the proposed increases to tax and penalties for these years of approximately $2.3 billion. We believe that the relevant transactions complied with applicable tax laws and did not violate judicial doctrines. We have filed U.S. income tax returns on this same basis for years after 2012. Based on the information currently available, we do not anticipate a significant increase or decrease to our unrecognized tax benefits for this matter within the next 12 months. We currently believe the ultimate disposition of this matter will not have a material adverse effect on our consolidated financial position, liquidity or results of operations.

Income taxes

The provision for income taxes for the first three months of 2018 reflects an estimated annual tax rate of 24 percent, compared to 32 percent for the first three months of 2017, excluding the discrete items discussed in the following paragraph. The decrease is primarily due to the reduction in the U.S. corporate tax rate beginning January 1, 2018, along with other changes in the geographic mix of profits from a tax perspective.

In addition, a discrete tax benefit of $40 million was recorded in the first three months of 2018, compared to $17 million in the first three months of 2017, for the settlement of stock-based compensation awards with associated tax deductions in excess of cumulative U.S. GAAP compensation expense. The provision for income taxes in the first three months of 2017 also included a $15 million increase to prior year taxes related to non-U.S. restructuring costs.

Our analysis of U.S. tax reform legislation, updated through March 31, 2018, resulted in no change to the 2017 year-end provisional charge of $2.371 billion. We will continue to update our calculations as additional required information is prepared and analyzed, interpretations and assumptions are refined, additional guidance is issued, and due to actions we may take as a result of the legislation. These updates could significantly impact the provision for income taxes, the amount of taxes payable and the deferred tax asset and liability balances.

On January 31, 2018, we received a Revenue Agent's Report from the Internal Revenue Service (IRS) indicating the end of the field examination of our U.S. income tax returns for 2010 to 2012. In the audits of 2007 to 2012 including the impact of a loss carryback to 2005, the IRS has proposed to tax in the United States profits earned from certain parts transactions by Caterpillar SARL, based on the IRS examination team's application of the "substance-over-form" or "assignment-of-income" judicial doctrines. We are vigorously contesting the proposed increases to tax and penalties for these years of approximately $2.3 billion. We believe that the relevant transactions complied with applicable tax laws and did not violate judicial doctrines. We have filed U.S. income tax returns on this same basis for years after 2012. Based on the information currently available, we do not anticipate a significant increase or decrease to our unrecognized tax benefits for this matter within the next 12 months. We currently believe the ultimate disposition of this matter will not have a material adverse effect on our consolidated financial position, liquidity or results of operations.