Organization	3 Months Ended
Organization	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	ORGANIZATION PacWest Bancorp, a Delaware corporation, is a bank holding company registered under the BHCA, with our corporate headquarters located in Beverly Hills, California. Our principal business is to serve as the holding company for our wholly-owned subsidiary, Pacific Western Bank. References to "Pacific Western" or the "Bank" refer to Pacific Western Bank together with its wholly-owned subsidiaries. References to "we," "us," or the "Company" refer to PacWest Bancorp together with its subsidiaries on a consolidated basis. When we refer to "PacWest" or to the "holding company," we are referring to PacWest Bancorp, the parent company, on a stand-alone basis. We are focused on relationship-based business banking to small, middle-market and venture-backed businesses nationwide. The Bank offers a broad range of loan and lease and deposit products and services through 69 full-service branches located in California, one branch located in Durham, North Carolina, one branch located in Denver, Colorado, and numerous loan production offices across the country. The Bank provides community banking products including lending and comprehensive deposit and treasury management services to small and medium-sized businesses conducted primarily through our California-based branch offices and Denver, Colorado branch office. The Bank offers national lending products including asset-based, equipment, and real estate loans and treasury management services to established middle-market businesses on a national basis. The Bank provides venture banking products including a comprehensive suite of financial services focused on entrepreneurial and venture-backed businesses and their venture capital and private equity investors, with offices located in key innovation hubs across the United States. The Bank also offers financing of business-purpose, non-owner-occupied investor properties through Civic, a wholly-owned subsidiary. The Bank also provides a specialized suite of services for the HOA industry. In addition, we provide investment advisory and asset management services to select clients through Pacific Western Asset Management Inc., a wholly-owned subsidiary of the Bank and an SEC-registered investment adviser. We generate our revenue primarily from interest received on loans and leases and, to a lesser extent, from interest received on investment securities, and fees received in connection with deposit services, extending credit and other services offered, including treasury management and investment management services. Our major operating expenses are interest paid by the Bank on deposits and borrowings, compensation, occupancy, and general operating expenses. Significant Accounting Policies Our accounting policies are described in Note 1. Nature of Operations and Summary of Significant Accounting Policies, of our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2021 as filed with the Securities and Exchange Commission ("Form 10-K"). Accounting Standards Adopted in 2022 Effective January 1, 2022, the Company partially adopted ASU 2022-02, “Financial Instruments – Credit Losses (Topic 326),” specifically the amendment related to the vintage disclosures, which requires creditors that are public entities to disclose current-period gross charge-offs by year of origination for financing receivables and net investments in leases within the scope of ASC 326-20, “Financial Instruments – Credit Losses – Measured at Amortized Cost.” The amendment also eliminates the disclosure of gross recoveries by year of origination previously presented in Example 15 in ASC 326-20-50-79, since it is not required under the guidance in ASC 326-20-50-6. The Company updated the vintage table disclosure in Note 4. Loans and Leases to present only current-period gross charge-offs by year of origination. The adoption of this amendment did not have a material impact on the Company’s condensed consolidated financial statements. Basis of Presentation Our interim condensed consolidated financial statements are prepared in accordance with U.S. GAAP for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X of the Securities Exchange Act of 1934. Accordingly, certain disclosures accompanying annual consolidated financial statements are omitted. In the opinion of management, all significant intercompany accounts and transactions have been eliminated and adjustments, consisting solely of normal recurring accruals and considered necessary for the fair presentation of financial statements for the interim periods, have been included. The current period's results of operations are not necessarily indicative of the results that ultimately may be achieved for the year. The interim condensed consolidated financial statements and notes thereto should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Form 10-K. Use of Estimates We have made a number of estimates and assumptions related to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period to prepare these condensed consolidated financial statements in conformity with U.S. GAAP. Actual results could differ from those estimates. Material estimates subject to change in the near term include, among other items, the allowance for credit losses (the combination of the allowance for loan and lease losses and the reserve for unfunded loan commitments), the carrying value of goodwill and other intangible assets, and the realization of deferred tax assets. These estimates may be adjusted as more current information becomes available, and any adjustment may be significant. Reclassifications Certain prior period amounts have been reclassified to conform to the current period’s presentation format. On the consolidated statements of earnings, new lines are presented for "Dividends and gains (losses) on equity investments" and "Warrant income," as those categories exceeded the disclosure materiality threshold in the fourth quarter of 2021, which previously had been included as part of "Other income."