Income Taxes	3 Months Ended
Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income taxes The provision for income taxes for the first quarter of 2015 reflects an estimated annual effective tax rate of 28.5 percent compared with 29.5 percent for the first quarter of 2014, excluding the items discussed below. The decrease is primarily due to a more favorable expected geographic mix of profits from a tax perspective in 2015. The impact of the U.S. research and development tax credit is not included in either the first quarter of 2015 or 2014 as it was renewed for 2014 in the fourth quarter of 2014 and has not been renewed for 2015. The provision for income taxes in the first quarter of 2014 also included a net charge of $22 million consisting of a $55 million charge to correct for an error which resulted in an understatement of tax liabilities for prior years offset by a $33 million benefit to reflect a settlement with the U.S. Internal Revenue Service (IRS) related to 1992 through 1994. On January 30, 2015, we received a Revenue Agent's Report (RAR) from the IRS indicating the end of the field examination of our U.S. tax returns for 2007 to 2009 including the impact of a loss carryback to 2005. The RAR proposed tax increases and penalties for these years of approximately $1 billion primarily related to two significant areas that we are vigorously contesting through the IRS Appeals process. In the first area, the IRS has proposed to tax in the United States profits earned from certain parts transactions by one of our non-U.S. subsidiaries, Caterpillar SARL (CSARL), based on the IRS examination team's application of the "substance-over-form" or "assignment-of-income" judicial doctrines. We believe that the relevant transactions complied with applicable tax laws and did not violate judicial doctrines. We have filed U.S. tax returns on this same basis for years after 2009. In the second area, the IRS disallowed approximately $125 million of foreign tax credits that arose as a result of certain financings unrelated to CSARL. Based on the information currently available, we do not anticipate a significant increase or decrease to our unrecognized tax benefits for these matters within the next 12 months. We currently believe the ultimate disposition of these matters will not have a material adverse effect on our consolidated financial position, liquidity or results of operations.

Income Taxes

3 Months Ended

Mar. 31, 2015

Income taxes

The provision for income taxes for the first quarter of 2015 reflects an estimated annual effective tax rate of 28.5 percent compared with 29.5 percent for the first quarter of 2014, excluding the items discussed below. The decrease is primarily due to a more favorable expected geographic mix of profits from a tax perspective in 2015. The impact of the U.S. research and development tax credit is not included in either the first quarter of 2015 or 2014 as it was renewed for 2014 in the fourth quarter of 2014 and has not been renewed for 2015.

The provision for income taxes in the first quarter of 2014 also included a net charge of $22 million consisting of a $55 million charge to correct for an error which resulted in an understatement of tax liabilities for prior years offset by a $33 million benefit to reflect a settlement with the U.S. Internal Revenue Service (IRS) related to 1992 through 1994.

On January 30, 2015, we received a Revenue Agent's Report (RAR) from the IRS indicating the end of the field examination of our U.S. tax returns for 2007 to 2009 including the impact of a loss carryback to 2005. The RAR proposed tax increases and penalties for these years of approximately $1 billion primarily related to two significant areas that we are vigorously contesting through the IRS Appeals process. In the first area, the IRS has proposed to tax in the United States profits earned from certain parts transactions by one of our non-U.S. subsidiaries, Caterpillar SARL (CSARL), based on the IRS examination team's application of the "substance-over-form" or "assignment-of-income" judicial doctrines. We believe that the relevant transactions complied with applicable tax laws and did not violate judicial doctrines. We have filed U.S. tax returns on this same basis for years after 2009. In the second area, the IRS disallowed approximately $125 million of foreign tax credits that arose as a result of certain financings unrelated to CSARL. Based on the information currently available, we do not anticipate a significant increase or decrease to our unrecognized tax benefits for these matters within the next 12 months. We currently believe the ultimate disposition of these matters will not have a material adverse effect on our consolidated financial position, liquidity or results of operations.