Critical Accounting Policies (Policies)	12 Months Ended
Critical Accounting Policies (Policies)	Dec. 31, 2017
Accounting Policies [Abstract]
Residual values for leased assets	Residual values for leased assets Lease residual values are an estimate of the market value of leased equipment at the end of the lease term and are based on an analysis of historical wholesale market sales prices, projected forward on a level trend line without consideration for inflation or possible future pricing action. At the inception of the lease, residual values are estimated with consideration of the following critical factors: market size and demand, any known significant market/product trends, total expected hours of usage, machine configuration, application, location, model changes, quantities, past remarketing experience, third-party residual guarantees and contractual customer purchase options. Many of these factors are gathered in an application survey that is completed prior to quotation. The lease agreement also clearly defines applicable return conditions and remedies for non-compliance, to ensure that the leased equipment will be in good operating condition upon return. Model changes and updates, as well as market strength and product acceptance, are monitored and adjustments are made to residual values in accordance with the significance of any such changes. Remarketing sales staff works closely with customers and dealers to manage the sale of lease returns and the recovery of residual exposure. During the term of the equipment on operating leases, we evaluate our depreciation on a regular basis taking into consideration expected residual values at lease termination. Adjustments to depreciation expense reflecting revised estimates of expected residual values at the end of the lease terms are recorded prospectively on a straight-line basis. For finance leases, residual value adjustments are recognized through a reduction of finance revenue. We evaluate the carrying value of equipment on operating leases for potential impairment when we determine a triggering event has occurred. When a triggering event occurs, a test for recoverability is performed by comparing projected undiscounted future cash flows to the carrying value of the equipment on operating leases. If the test for recoverability identifies a possible impairment, the fair value of the equipment on operating leases is measured in accordance with the fair value measurement framework. An impairment charge is recognized for the amount by which the carrying value of the equipment on operating leases exceeds its estimated fair value. At December 31, 2017, the aggregate residual value of equipment on operating leases was $2.20 billion. Without consideration of other factors such as third-party residual guarantees or contractual customer purchase options, a 10 percent non-temporary decrease in the market value of our equipment subject to operating leases would reduce residual value estimates and result in recognition of approximately $80 million of additional annual depreciation expense.
Allowance for credit losses	Allowance for credit losses The allowance for credit losses is an estimate of the losses inherent in our finance receivable portfolio and includes consideration of accounts that have been individually identified as impaired, as well as pools of finance receivables where it is probable that certain receivables in the pool are impaired but the individual accounts cannot yet be identified. In identifying and measuring impairment, management takes into consideration past loss experience, known and inherent risks in the portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of underlying collateral and current economic conditions. Accounts are identified for individual review based on past-due status and information available about the customer, such as financial statements, news reports and published credit ratings, as well as general information regarding industry trends and the economic environment in which our customers operate. The allowance for credit losses attributable to finance receivables that are individually evaluated and determined to be impaired is based on the present value of expected future cash flows discounted at the receivables' effective interest rate, the fair value of the collateral for collateral-dependent receivables or the observable market price of the receivable. In determining collateral value, we estimate the current fair market value of the collateral less selling costs. We also consider credit enhancements such as additional collateral and contractual third-party guarantees. The allowance for credit losses attributable to the remaining accounts not yet individually identified as impaired is estimated based on loss forecast models utilizing probabilities of default, our estimate of the loss emergence period and the estimated loss given default. In addition, qualitative factors not able to be fully captured in our loss forecast models including industry trends, macroeconomic factors and model imprecision are considered in the evaluation of the adequacy of the allowance for credit losses. These qualitative factors are subjective and require a degree of management judgment. While management believes it has exercised prudent judgment and applied reasonable assumptions, there can be no assurance that in the future, changes in economic conditions or other factors would not cause changes in the financial health of our customers. If the financial health of our customers deteriorates, the timing and level of payments received could be impacted and therefore, could result in a change to our estimated losses.
Income taxes	Income taxes We are subject to the income tax laws of the many jurisdictions in which we operate. These tax laws are complex, and the manner in which they apply to our facts is sometimes open to interpretation. In establishing the provision for income taxes, we must make judgments about the application of these inherently complex tax laws. Despite our belief that our tax return positions are consistent with applicable tax laws, we believe that taxing authorities could challenge certain positions. Settlement of any challenge can result in no change, a complete disallowance, or some partial adjustment reached through negotiations or litigation. We record tax benefits for uncertain tax positions based upon management's evaluation of the information available at the reporting date. To be recognized in the financial statements, a tax benefit must be at least more likely than not of being sustained based on technical merits. The benefit for positions meeting the recognition threshold is measured as the largest benefit more likely than not of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. Significant judgment is required in making these determinations and adjustments to unrecognized tax benefits may be necessary to reflect actual taxes payable upon settlement. Adjustments related to positions impacting the effective tax rate affect the provision for income taxes. Adjustments related to positions impacting the timing of deductions impact deferred tax assets and liabilities. Income taxes are based on the statutory tax rate of the jurisdiction in which earnings are subject to taxation. That statutory rate may differ from the statutory tax rate of the jurisdiction in which that entity is incorporated. Taxes are paid in the jurisdictions where earnings are subject to taxation. The effective tax rate differs from the U.S. statutory rate in part due to profits of non-U.S. subsidiaries being subject to statutory tax rates which were generally lower than the U.S. rate of 35 percent effective prior to January 1, 2018. Our income tax positions and analysis are based on currently enacted tax law. On December 22, 2017, U.S. tax legislation was enacted containing a broad range of tax reform provisions including a corporate tax rate reduction and changes in the U.S. taxation of non-U.S. earnings. We have not completed our accounting for the income tax effects of U.S. tax reform. However, we have made a reasonable estimate of the 2017 financial statement impact as of January 18, 2018, and recognized a provisional net benefit of $151 million. 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. The provisionally estimated net benefit includes a $334 million write-down of net deferred tax liabilities to reflect the reduction in the U.S. corporate tax rate from 35 percent to 21 percent beginning January 1, 2018. We are still analyzing certain aspects of the law and refining our calculations of basis differences as of December 31, 2017, which could affect the measurement of these balances. The provisionally estimated net benefit includes $183 million for the estimated cost of a mandatory deemed repatriation of non-U.S. earnings. The resulting tax liability, net of available foreign tax credits, is $131 million, payable over eight years and is included in Income taxes payable in the Consolidated Statements of Financial Position. The U.S. federal tax cost for the mandatory deemed repatriation is computed at 15.5 percent for non-U.S. earnings held in liquid assets and 8 percent for non-liquid assets, reduced by applicable foreign tax credits. These estimates are provisional due to additional information and analysis required to determine cumulative taxable earnings since 1986 for non-U.S. subsidiaries at two separate points in time and to determine the amount of earnings that are held in liquid versus non-liquid assets as defined in the new legislation at several different measurement periods. In addition, information is being gathered and analyzed to support available foreign tax credits including estimates of credit utilization and valuation allowance considerations for any remaining foreign tax credit carryforward. Due to uncertainty about aspects of the tax law, we have made various assumptions to determine our reasonable estimate that we expect to refine as additional guidance is issued. As a result of U.S. tax reform legislation, distributions of profits from non-U.S. subsidiaries are expected to have minimal U.S. tax impact in the future. However, these distributions may be subject to non-U.S. withholding taxes if profits are distributed from certain jurisdictions. We have not recorded a deferred tax liability for withholding taxes in non-U.S. jurisdictions where earnings are considered indefinitely reinvested. If management intentions or U.S. tax law changes in the future, there could be an impact on the provision for income taxes to record an incremental tax liability in the period the change occurs. Deferred tax assets generally represent tax benefits for tax deductions or credits available in future tax returns. Certain estimates and assumptions are required to determine whether it is more likely than not that all or some portion of the benefit of a deferred tax asset will not be realized. In making this assessment, management analyzes the trend of U.S. GAAP earnings and estimates the impact of future taxable income, reversing temporary differences and available prudent and feasible tax planning strategies. Should a change in facts or circumstances lead to a change in judgment about the ultimate realizability of a deferred tax asset, we record or adjust the related valuation allowance in the period that the change in facts and circumstances occurs, along with a corresponding increase or decrease in the provision for income taxes.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.