Summary of Significant Accounting Policies and Nature of Operations	6 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Nature of Operations	Summary of Significant Accounting Policies and Nature of OperationsMUFG Americas Holdings Corporation (MUAH or the Company) is a financial holding company, bank holding company and intermediate holding company whose principal subsidiaries are MUFG Union Bank, N.A. (MUB or the Bank) and MUFG Securities Americas Inc. (MUSA). MUAH provides a wide range of financial services to consumers, small businesses, middle-market companies and major corporations nationally and internationally. The Company also provides various business, banking, financial, administrative and support services, and facilities for MUFG Bank, Ltd. in connection with the operation and administration of MUFG Bank, Ltd.'s business in the U.S. (including MUFG Bank, Ltd.'s U.S. branches). All of the Company's issued and outstanding shares of common stock are owned by MUFG Bank, Ltd. and MUFG. The unaudited consolidated financial statements of MUAH, its subsidiaries, and its consolidated variable interest entities have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial reporting and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the Rules and Regulations of the SEC. However, they do not include all of the disclosures necessary for annual financial statements. In the opinion of management, all adjustments, consisting of normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the second quarter of 2021 are not necessarily indicative of the operating results anticipated for the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020 (2020 Form 10-K). The preparation of financial statements in conformity with GAAP also requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Although such estimates contemplate current conditions and management’s expectations of how they may change in the future, it is reasonably possible that actual results could differ significantly from those estimates. This could materially affect the Company’s results of operations and financial condition in the near term. Critical estimates made by management in the preparation of the Company’s financial statements include, but are not limited to, the allowance for credit losses (Note 3 "Loans and Allowance for Loan Losses"), goodwill impairment, income taxes, and transfer pricing.

Summary of Significant Accounting Policies and Nature of Operations

6 Months Ended

Jun. 30, 2021

Summary of Significant Accounting Policies and Nature of Operations

Summary of Significant Accounting Policies and Nature of OperationsMUFG Americas Holdings Corporation (MUAH or the Company) is a financial holding company, bank holding company and intermediate holding company whose principal subsidiaries are MUFG Union Bank, N.A. (MUB or the Bank) and MUFG Securities Americas Inc. (MUSA). MUAH provides a wide range of financial services to consumers, small businesses, middle-market companies and major corporations nationally and internationally. The Company also provides various business, banking, financial, administrative and support services, and facilities for MUFG Bank, Ltd. in connection with the operation and administration of MUFG Bank, Ltd.'s business in the U.S. (including MUFG Bank, Ltd.'s U.S. branches). All of the Company's issued and outstanding shares of common stock are owned by MUFG Bank, Ltd. and MUFG. The unaudited consolidated financial statements of MUAH, its subsidiaries, and its consolidated variable interest entities have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial reporting and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the Rules and Regulations of the SEC. However, they do not include all of the disclosures necessary for annual financial statements. In the opinion of management, all adjustments, consisting of normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the second quarter of 2021 are not necessarily indicative of the operating results anticipated for the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020 (2020 Form 10-K). The preparation of financial statements in conformity with GAAP also requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Although such estimates contemplate current conditions and management’s expectations of how they may change in the future, it is reasonably possible that actual results could differ significantly from those estimates. This could materially affect the Company’s results of operations and financial condition in the near term. Critical estimates made by management in the preparation of the Company’s financial statements include, but are not limited to, the allowance for credit losses (Note 3 "Loans and Allowance for Loan Losses"), goodwill impairment, income taxes, and transfer pricing.