Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2021
Significant Accounting Policies [Line Items]
Business Description and Basis of Presentation	Wells Fargo & Company is a diversified financial services company. We provide banking, investment and mortgage products and services, as well as consumer and commercial finance, through banking locations and offices, the internet and other distribution channels to individuals, businesses and institutions in all 50 states, the District of Columbia, and in countries outside the U.S. When we refer to “Wells Fargo,” “the Company,” “we,” “our” or “us,” we mean Wells Fargo & Company and Subsidiaries (consolidated). Wells Fargo & Company (the Parent) is a financial holding company and a bank holding company. We also hold a majority interest in a real estate investment trust, which has publicly traded preferred stock outstanding. Our accounting and reporting policies conform with U.S. generally accepted accounting principles (GAAP) and practices in the financial services industry. For discussion of our significant accounting policies, see Note 1 (Summary of Significant Accounting Policies) in our Annual Report on Form 10-K for the year ended December 31, 2020 (2020 Form 10-K).
Use of Estimates	To prepare the financial statements in conformity with GAAP, management must make estimates based on assumptions about future economic and market conditions (for example, unemployment, market liquidity, real estate prices, etc.) that affect the reported amounts of assets and liabilities at the date of the financial statements, income and expenses during the reporting period and the related disclosures. Although our estimates contemplate current conditions and how we expect them to change in the future, it is reasonably possible that actual conditions could be worse than anticipated in those estimates, which could materially affect our results of operations and financial condition. Management has made significant estimates in several areas, including: •allowance for credit losses (Note 4 (Loans and Related Allowance for Credit Losses)); •valuations of residential mortgage servicing rights (MSRs) (Note 8 (Securitizations and Variable Interest Entities) and Note 9 (Mortgage Banking Activities)); •valuations of financial instruments (Note 15 (Fair Values of Assets and Liabilities)); •liabilities for contingent litigation losses (Note 13 (Legal Actions)); •income taxes; and •goodwill impairment (Note 10 (Intangible Assets)). Actual results could differ from those estimates. These unaudited interim financial statements reflect all adjustments that are, in the opinion of management, necessary for a fair statement of the results for the periods presented. These adjustments are of a normal recurring nature, unless otherwise disclosed in this Form 10-Q. The results of operations in the interim financial statements do not necessarily indicate the results that may be expected for the full year. The interim financial information should be read in conjunction with our 2020 Form 10-K.
Change in Accounting Policies	Change in Accounting Policies In second quarter 2021, we elected to change our accounting method for low-income housing tax credit (LIHTC) investments from the equity method of accounting to the proportional amortization method. Under the proportional amortization method, the investments are carried at amortized cost and amortized in proportion to the tax credits received. The amortization of the investments and the related tax impacts are recognized in income tax expense. Previously, we recognized the amortization of the investments in other noninterest income and the related tax impacts were recognized in income tax expense. We determined that the proportional amortization method is preferable because it better aligns the financial statement presentation with the economic impact of these investments, which generate tax credits over the lives of the investments. Adoption of the proportional amortization method was applied retrospectively, to the earliest period presented, which resulted in a cumulative-effect adjustment to reduce retained earnings by $283 million as of January 1, 2020. In second quarter 2021, we also elected to change the presentation of investment tax credits related to solar energy investments, which are accounted for under the deferral method. We reclassified the investment tax credits on our consolidated balance sheet from accrued expenses and other liabilities to a reduction of the carrying value of the investment balances. We also reclassified the investment tax credits, which are recognized over time, from income tax expense to interest income for solar energy leases or noninterest income for solar energy equity investments. We determined that this presentation is preferable because it better reflects the financial statement presentation of the investment tax credits as an integral component of the investments. The change in accounting policy was adopted retrospectively to January 1, 2020.
Accounting Standards Adopted in 2021	Accounting Standards Adopted in 2021 In 2021, we adopted the following new accounting guidance: •Accounting Standards Update (ASU or Update) 2021-01 – Reference Rate Reform (Topic 848): Scope •ASU 2020-08 – Codification Improvements to Subtopic 310-20, Receivables – Nonrefundable Fees and Other Costs •ASU 2020-01 – Investments – Equity Securities (Topic 321), Investments – Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815): Clarifying the Interactions between Topic 321, Topic 323, and Topic 815 (a consensus of the Financial Accounting Standards Board (FASB) Emerging Issues Task Force) •ASU 2019-12 – Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes
Subsequent Events	Subsequent Events On November 1, 2021, we closed our previously announced agreement to sell our Corporate Trust Services business and our previously announced agreement to sell Wells Fargo Asset Management, which is subject to certain post-closing adjustments and earn-out provisions. We have evaluated the effects of events that have occurred subsequent to September 30, 2021, and, except for the closing of the sales of our Corporate Trust Services business and Wells Fargo Asset Management, there have been no material events that would require recognition in our third quarter 2021 consolidated financial statements or disclosure in the Notes to the consolidated financial statements.
Accounting Standards Update 2021-01 [Member]
Significant Accounting Policies [Line Items]
Accounting Standards Adopted in 2021	ASU 2021-01 clarifies the scope of Topic 848 to include derivatives affected by changes in interest rates for margining, discounting, or contract price alignment as part of the market-wide transition to new reference rates (commonly referred to as the “discounting transition”), even if they do not reference the London Interbank Offered Rate or another rate that is expected to be discontinued as a result of reference rate reform. The Update also clarifies other aspects of the relief provided in Accounting Standards Codification (ASC) 848. We adopted this Update in first quarter 2021 on a prospective basis, and the guidance will be followed until the Update terminates on December 31, 2022. The Update did not have a material impact on our consolidated financial statements.
Accounting Standards Update 2020-08 [Member]
Significant Accounting Policies [Line Items]
Accounting Standards Adopted in 2021	ASU 2020-08 clarifies the accounting for purchased callable debt securities carried at a premium and was issued to correct an unintended application of ASU 2017-08 – Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, which requires amortization of such premiums to the earliest call date, but was not clear for the method to be used for instruments with multiple call dates. The Update now specifies that such premiums are amortized to the next call date and requires reassessment throughout the life of the instruments with multiple call dates. We adopted this Update in first quarter 2021. The Update did not have a material impact on our consolidated financial statements.
Accounting Standards Update 2020-01 [Member]
Significant Accounting Policies [Line Items]
Accounting Standards Adopted in 2021	ASU 2020-01 clarifies the accounting for equity securities upon transition between the measurement alternative and equity method. The Update also clarifies for forward contracts and options to purchase equity securities an entity need not consider whether upon settlement of the forward contract or option if the equity securities would be accounted for by the equity method or the fair value option. We adopted this Update in first quarter 2021. The Update did not have a material impact on our consolidated financial statements.
Accounting Standards Update 2019-12 [Member]
Significant Accounting Policies [Line Items]
Accounting Standards Adopted in 2021	ASU 2019-12 provides narrow scope simplifications and improvements to the general principles in ASC Topic 740 – Income Taxes related to intraperiod tax allocation, basis differences when there are changes in ownership of foreign investments and interim periods income tax accounting for year to date losses that exceed anticipated annual losses. We adopted this Update in first quarter 2021. The Update did not have a material impact on our consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2021

Significant Accounting Policies [Line Items]

Business Description and Basis of Presentation

Wells Fargo & Company is a diversified financial services company. We provide banking, investment and mortgage products and services, as well as consumer and commercial finance, through banking locations and offices, the internet and other distribution channels to individuals, businesses and institutions in all 50 states, the District of Columbia, and in countries outside the U.S. When we refer to “Wells Fargo,” “the Company,” “we,” “our” or “us,” we mean Wells Fargo & Company and Subsidiaries (consolidated). Wells Fargo & Company (the Parent) is a financial holding company and a bank holding company. We also hold a majority interest in a real estate investment trust, which has publicly traded preferred stock outstanding.

Our accounting and reporting policies conform with U.S. generally accepted accounting principles (GAAP) and practices in the financial services industry. For discussion of our significant accounting policies, see Note 1 (Summary of Significant Accounting Policies) in our Annual Report on Form 10-K for the year ended December 31, 2020 (2020 Form 10-K).

Use of Estimates

To prepare the financial statements in conformity with GAAP, management must make estimates based on assumptions about future economic and market conditions (for example, unemployment, market liquidity, real estate prices, etc.) that affect the reported amounts of assets and liabilities at the date of the financial statements, income and expenses during the reporting period and the related disclosures. Although our estimates contemplate current conditions and how we expect them to change in the future, it is reasonably possible that actual conditions could be worse than anticipated in those estimates, which could materially affect our results of operations and financial condition. Management has made significant estimates in several areas, including:

•allowance for credit losses (Note 4 (Loans and Related Allowance for Credit Losses));

•valuations of residential mortgage servicing rights (MSRs) (Note 8 (Securitizations and Variable Interest Entities) and Note 9 (Mortgage Banking Activities));

•valuations of financial instruments (Note 15 (Fair Values of Assets and Liabilities));

•liabilities for contingent litigation losses (Note 13 (Legal Actions));

•income taxes; and

•goodwill impairment (Note 10 (Intangible Assets)).

Actual results could differ from those estimates.

These unaudited interim financial statements reflect all adjustments that are, in the opinion of management, necessary for a fair statement of the results for the periods presented. These adjustments are of a normal recurring nature, unless otherwise disclosed in this Form 10-Q. The results of operations in the interim financial statements do not necessarily indicate the results that may be expected for the full year. The interim financial information should be read in conjunction with our 2020 Form 10-K.

Change in Accounting Policies

In second quarter 2021, we elected to change our accounting method for low-income housing tax credit (LIHTC) investments from the equity method of accounting to the proportional amortization method. Under the proportional amortization method, the investments are carried at amortized cost and amortized in proportion to the tax credits received. The amortization of the investments and the related tax impacts are recognized in income tax expense. Previously, we recognized the amortization of the investments in other noninterest income and the related tax impacts were recognized in income tax expense. We determined that the proportional amortization method is preferable because it better aligns the financial statement presentation with the economic impact of these investments, which generate tax credits over the lives of the investments. Adoption of the proportional amortization method was applied retrospectively, to the earliest period presented, which resulted in a cumulative-effect adjustment to reduce retained earnings by $283 million as of January 1, 2020.

In second quarter 2021, we also elected to change the presentation of investment tax credits related to solar energy investments, which are accounted for under the deferral method. We reclassified the investment tax credits on our consolidated balance sheet from accrued expenses and other liabilities to a reduction of the carrying value of the investment balances. We also reclassified the investment tax credits, which are recognized over time, from income tax expense to interest income for solar energy leases or noninterest income for solar energy equity investments. We determined that this presentation is preferable because it better reflects the financial statement presentation of the investment tax credits as an integral component of the investments. The change in accounting policy was adopted retrospectively to January 1, 2020.

Accounting Standards Adopted in 2021

In 2021, we adopted the following new accounting guidance:

•Accounting Standards Update (ASU or Update) 2021-01 – Reference Rate Reform (Topic 848): Scope

•ASU 2020-08 – Codification Improvements to Subtopic 310-20, Receivables – Nonrefundable Fees and Other Costs

•ASU 2020-01 – Investments – Equity Securities (Topic 321), Investments – Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815): Clarifying the Interactions between Topic 321, Topic 323, and Topic 815 (a consensus of the Financial Accounting Standards Board (FASB) Emerging Issues Task Force)

•ASU 2019-12 – Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Subsequent Events

Subsequent Events On November 1, 2021, we closed our previously announced agreement to sell our Corporate Trust Services business and our previously announced agreement to sell Wells Fargo Asset Management, which is subject to certain post-closing adjustments and earn-out provisions. We have evaluated the effects of events that have occurred subsequent to September 30, 2021, and, except for the closing of the sales of our Corporate Trust Services business and Wells Fargo Asset Management, there have been no material events that would require recognition in our third quarter 2021 consolidated financial statements or disclosure in the Notes to the consolidated financial statements.

Accounting Standards Update 2021-01 [Member]

Significant Accounting Policies [Line Items]

Accounting Standards Adopted in 2021

ASU 2021-01 clarifies the scope of Topic 848 to include derivatives affected by changes in interest rates for margining, discounting, or contract price alignment as part of the market-wide transition to new reference rates (commonly referred to as the “discounting transition”), even if they do not reference the London Interbank Offered Rate or another rate that is expected to be discontinued as a result of reference rate reform. The Update also clarifies other aspects of the relief provided in Accounting Standards Codification (ASC) 848. We adopted this Update in first quarter 2021 on a prospective basis, and the guidance will be followed until the Update terminates on December 31, 2022. The Update did not have a material impact on our consolidated financial statements.

Accounting Standards Update 2020-08 [Member]

Significant Accounting Policies [Line Items]

Accounting Standards Adopted in 2021

ASU 2020-08 clarifies the accounting for purchased callable debt securities carried at a premium and was issued to correct an unintended application of ASU 2017-08 – Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, which requires amortization of such premiums to the earliest call date, but was not clear for the method to be used for instruments with multiple call dates. The Update now specifies that such premiums are amortized to the next call date and requires reassessment throughout the life of the instruments with multiple call dates. We adopted this Update in first quarter 2021. The Update did not have a material impact on our consolidated financial statements.

Accounting Standards Update 2020-01 [Member]

Significant Accounting Policies [Line Items]

Accounting Standards Adopted in 2021

ASU 2020-01 clarifies the accounting for equity securities upon transition between the measurement alternative and equity method. The Update also clarifies for forward contracts and options to purchase equity securities an entity need not consider whether upon settlement of the forward contract or option if the equity securities would be accounted for by the equity method or the fair value option. We adopted this Update in first quarter 2021. The Update did not have a material impact on our consolidated financial statements.

Accounting Standards Update 2019-12 [Member]

Significant Accounting Policies [Line Items]

Accounting Standards Adopted in 2021

ASU 2019-12 provides narrow scope simplifications and improvements to the general principles in ASC Topic 740 – Income Taxes related to intraperiod tax allocation, basis differences when there are changes in ownership of foreign investments and interim periods income tax accounting for year to date losses that exceed anticipated annual losses. We adopted this Update in first quarter 2021. The Update did not have a material impact on our consolidated financial statements.