Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements include our accounts and the accounts of our consolidated subsidiaries, including certain special purpose entities (SPEs) utilized in secured financing transactions, which are considered variable interest entities (VIEs). All intercompany balances and transactions have been eliminated in consolidation. The consolidated financial statements, including the notes thereto, are condensed and do not include all disclosures required by generally accepted accounting principles (GAAP) in the U.S. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements that are included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019, as filed with the Securities and Exchange Commission (SEC) on February 5, 2020 (2019 Form 10-K). Except as otherwise specified, dollar amounts presented within tables are stated in millions. The condensed consolidated financial statements at September 30, 2020, and for the three and nine months ended September 30, 2020 and 2019, are unaudited and, in management’s opinion, include all adjustments, which consist of normal recurring adjustments and transactions or events discretely impacting the interim periods, considered necessary by management to fairly state our results of operations. The results for interim periods are not necessarily indicative of results for a full year. The condensed consolidated balance sheet at December 31, 2019 was derived from audited annual financial statements.
Segment Information	Segment Information We are the wholly-owned captive finance subsidiary of General Motors Company (GM). We offer substantially similar products and services throughout many different regions, subject to local regulations and market conditions. We evaluate our business in two operating segments: North America (the North America Segment) and International (the International Segment). Our North America Segment includes operations in the U.S. and Canada. Our International Segment includes operations in Brazil, Chile, Colombia, Mexico and Peru, as well as our equity investments in joint ventures in the Asia/Pacific region.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards Effective January 1, 2020, we adopted Accounting Standards Update (ASU) 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments" (ASU 2016-13), which requires entities to use a new impairment model based on current expected credit losses (CECL) rather than incurred losses. Estimated credit losses under CECL consider relevant information about past events, current conditions and reasonable and supportable forecasts that affect the collectability of finance receivables, resulting in recognition of lifetime expected credit losses upon origination of the related finance receivable. We adopted ASU 2016-13 on a modified retrospective basis on January 1, 2020 by recognizing an after-tax cumulative-effect adjustment to the opening balance of retained earnings of $643 million. The application of ASU 2016-13 increased our allowance for loan losses by $801 million. The following updates to our accounting policies became effective upon the adoption of ASU 2016-13. Retail Finance Receivables and the Allowance for Loan Losses Our retail finance receivables portfolio consists of smaller-balance, homogeneous loans that are carried at amortized cost, net of allowance for loan losses. These loans are divided among pools based on common risk characteristics, such as internal credit score, origination period (vintage) and geography. An internal credit score, of which FICO is an input in North America, is created by using algorithms or statistical models contained in origination scorecards. The scorecards are used to evaluate a consumer’s ability to pay based on statistical modeling of his or her prior credit usage, structure of the loan and other information. The output of the scorecards rank-orders consumers from those that are least likely to default to those that are most likely to default. By further dividing the portfolio into pools based on internal credit scores, we are better able to distinguish expected credit performance for different credit risks. The allowance is aggregated for each of the pools. Provisions for loan losses are charged to operations in amounts sufficient to maintain the allowance for loan losses at levels considered adequate to cover expected credit losses on our retail finance receivables portfolio. We use static pool modeling techniques to determine the allowance for loan losses expected over the remaining life of the receivables, which is supplemented by management judgment. We assess the recent internal operating and external environments and may qualitatively adjust certain assumptions to result in an allowance that is more reflective of losses that are expected to occur in the forecast environment. Expected losses are estimated for groups of accounts aggregated by internal credit score and monthly vintage. Generally, the expected losses are projected based on historical loss experience over the last ten years, more heavily weighted toward recent performance when determining the allowance to result in an estimate that is more reflective of the current internal and external environments. We consider forecast economic conditions over a reasonable and supportable forecast period. We determine the expected remaining life of the finance receivables to be a reasonable and supportable forecast horizon, primarily due to the relatively short weighted average life of retail finance receivables. We determined the economic factors that have the largest impact on expected losses include unemployment rates, interest rate spreads, disposable personal income, and growth rates in gross domestic products. We use forecasts for our chosen factors provided by a leading economic research firm. We compare the forecasts to consensus forecasts to assess for reasonableness and may use one or more forecast scenarios provided by the research firm. Troubled debt restructurings (TDRs) are grouped separately for purposes of measuring the allowance. The allowance for TDRs uses static pool modeling techniques, similar to non-TDR retail finance receivables, to determine the expected loss amount. The expected cash flows of the receivables are then discounted at the original weighted average effective interest rate of the pool. Factors considered when estimating the TDR allowance are based on an evaluation of historical and current information, and may be supplemented by management judgment. While we expect certain of our finance receivables to become TDRs, there is typically no delay between the point at which we become aware that a receivable is expected to become a TDR and when the receivable actually qualifies as a TDR. Therefore, our TDR portfolio does not include any receivables that are expected to become TDRs. We believe these factors are relevant in estimating expected losses and also consider an evaluation of overall portfolio credit quality based on indicators such as changes in our credit evaluation, underwriting and collection management policies, changes in the legal and regulatory environment, general economic conditions and business trends and uncertainties in forecasting and modeling techniques used in estimating our allowance. We update our retail loss forecast models and portfolio indicators on a quarterly basis to incorporate information reflective of the current and forecast economic environments. Assumptions regarding credit losses are reviewed periodically and may be impacted by actual performance of finance receivables and changes in any of the factors discussed above. Should the credit loss assumptions increase, there would be an increase in the amount of allowance for loan losses required, which would decrease the net carrying value of finance receivables and increase the amount of provision for loan losses. Commercial Finance Receivables and the Allowance for Loan Losses Our commercial lending offerings consist of floorplan financing as well as dealer loans, which are loans to finance improvements to dealership facilities, to provide working capital, and to purchase and/or finance dealership real estate. Commercial finance receivables are carried at amortized cost, net of allowance for loan losses and any amounts held under a cash management program. Provisions for loan losses are charged to operations in amounts sufficient to maintain the allowance for loan losses at levels considered adequate to cover expected credit losses in the commercial finance receivables portfolio. We establish the allowance for loan losses based on historical loss experience, as well as the forecast for industry vehicle sales, which is the economic indicator that we believe has the largest impact on expected losses. The commercial finance receivables are aggregated into loan-risk pools, which are determined based on our internally-developed risk rating system. Dealers' financial and operating metrics are regularly scored and further evaluated to derive a risk rating. Based on dealer risk ratings, we establish probability of default and loss given default, and also determine if any specific dealer loan requires additional reserves. In March 2020, the Financial Accounting Standards Board issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting” (ASU 2020-04), which provides optional expedients and exceptions for applying U.S. GAAP if certain criteria are met to contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued. A substantial portion of our indebtedness bears interest at variable interest rates, primarily based on USD-LIBOR. Effective July 1, 2020, we adopted ASU 2020-04 on a prospective basis. The adoption of, and future elections under, ASU 2020-04 are not expected to have a material impact on our consolidated financial statements as the standard will ease, if warranted, the requirements for accounting for the future effects of the rate reform. We continue to monitor the impact the discontinuance of LIBOR or another reference rate will have on our contracts, hedging relationships and other transactions.

Effective January 1, 2020, we adopted Accounting Standards Update (ASU) 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments" (ASU 2016-13), which requires entities to use a new impairment model based on current expected credit losses (CECL) rather than incurred losses. Estimated credit losses under CECL consider relevant information about past events, current conditions and reasonable and supportable forecasts that affect the collectability of finance receivables, resulting in recognition of lifetime expected credit losses upon origination of the related finance receivable. We adopted ASU 2016-13 on a modified retrospective basis on January 1, 2020 by recognizing an after-tax cumulative-effect adjustment to the opening balance of retained earnings of $643 million. The application of ASU 2016-13 increased our allowance for loan losses by $801 million. The following updates to our accounting policies became effective upon the adoption of ASU 2016-13.

Retail Finance Receivables and the Allowance for Loan Losses Our retail finance receivables portfolio consists of smaller-balance, homogeneous loans that are carried at amortized cost, net of allowance for loan losses. These loans are divided among pools based on common risk characteristics, such as internal credit score, origination period (vintage) and geography. An internal credit score, of which FICO is an input in North America, is created by using algorithms or statistical models contained in origination scorecards. The scorecards are used to evaluate a consumer’s ability to pay based on statistical modeling of his or her prior credit usage, structure of the loan and other information. The output of the scorecards rank-orders consumers from those that are least likely to default to those that are most likely to default. By further dividing the portfolio into pools based on internal credit scores, we are better able to distinguish expected credit performance for different credit risks. The allowance is aggregated for each of the pools. Provisions for loan losses are charged to operations in amounts sufficient to maintain the allowance for loan losses at levels considered adequate to cover expected credit losses on our retail finance receivables portfolio.

We use static pool modeling techniques to determine the allowance for loan losses expected over the remaining life of the receivables, which is supplemented by management judgment. We assess the recent internal operating and external environments and may qualitatively adjust certain assumptions to result in an allowance that is more reflective of losses that are expected to occur in the forecast environment.

Expected losses are estimated for groups of accounts aggregated by internal credit score and monthly vintage. Generally, the expected losses are projected based on historical loss experience over the last ten years, more heavily weighted toward recent performance when determining the allowance to result in an estimate that is more reflective of the current internal and external environments. We consider forecast economic conditions over a reasonable and supportable forecast period. We

determine the expected remaining life of the finance receivables to be a reasonable and supportable forecast horizon, primarily due to the relatively short weighted average life of retail finance receivables. We determined the economic factors that have the largest impact on expected losses include unemployment rates, interest rate spreads, disposable personal income, and growth rates in gross domestic products. We use forecasts for our chosen factors provided by a leading economic research firm. We compare the forecasts to consensus forecasts to assess for reasonableness and may use one or more forecast scenarios provided by the research firm.

Troubled debt restructurings (TDRs) are grouped separately for purposes of measuring the allowance. The allowance for TDRs uses static pool modeling techniques, similar to non-TDR retail finance receivables, to determine the expected loss amount. The expected cash flows of the receivables are then discounted at the original weighted average effective interest rate of the pool. Factors considered when estimating the TDR allowance are based on an evaluation of historical and current information, and may be supplemented by management judgment. While we expect certain of our finance receivables to become TDRs, there is typically no delay between the point at which we become aware that a receivable is expected to become a TDR and when the receivable actually qualifies as a TDR. Therefore, our TDR portfolio does not include any receivables that are expected to become TDRs.

We believe these factors are relevant in estimating expected losses and also consider an evaluation of overall portfolio credit quality based on indicators such as changes in our credit evaluation, underwriting and collection management policies, changes in the legal and regulatory environment, general economic conditions and business trends and uncertainties in forecasting and modeling techniques used in estimating our allowance. We update our retail loss forecast models and portfolio indicators on a quarterly basis to incorporate information reflective of the current and forecast economic environments.

Assumptions regarding credit losses are reviewed periodically and may be impacted by actual performance of finance receivables and changes in any of the factors discussed above. Should the credit loss assumptions increase, there would be an increase in the amount of allowance for loan losses required, which would decrease the net carrying value of finance receivables and increase the amount of provision for loan losses.

Commercial Finance Receivables and the Allowance for Loan Losses Our commercial lending offerings consist of floorplan financing as well as dealer loans, which are loans to finance improvements to dealership facilities, to provide working capital, and to purchase and/or finance dealership real estate.

Commercial finance receivables are carried at amortized cost, net of allowance for loan losses and any amounts held under a cash management program. Provisions for loan losses are charged to operations in amounts sufficient to maintain the allowance for loan losses at levels considered adequate to cover expected credit losses in the commercial finance receivables portfolio. We establish the allowance for loan losses based on historical loss experience, as well as the forecast for industry vehicle sales, which is the economic indicator that we believe has the largest impact on expected losses. The commercial finance receivables are aggregated into loan-risk pools, which are determined based on our internally-developed risk rating system. Dealers' financial and operating metrics are regularly scored and further evaluated to derive a risk rating. Based on dealer risk ratings, we establish probability of default and loss given default, and also determine if any specific dealer loan requires additional reserves.

In March 2020, the Financial Accounting Standards Board issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting” (ASU 2020-04), which provides optional expedients and exceptions for applying U.S. GAAP if certain criteria are met to contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued. A substantial portion of our indebtedness bears interest at variable interest rates, primarily based on USD-LIBOR.

Effective July 1, 2020, we adopted ASU 2020-04 on a prospective basis. The adoption of, and future elections under, ASU 2020-04 are not expected to have a material impact on our consolidated financial statements as the standard will ease, if warranted, the requirements for accounting for the future effects of the rate reform. We continue to monitor the impact the discontinuance of LIBOR or another reference rate will have on our contracts, hedging relationships and other transactions.