Nature of Operations and Basis Of Presentation (Policies)	3 Months Ended
	Mar. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature Of Operations	Nature of Operations Stifel Financial Corp. (the “Company”), through its wholly owned subsidiaries, is principally engaged in retail brokerage; securities trading; investment banking; investment advisory; retail, consumer, and commercial banking; and related financial services. We have offices throughout the United States and Europe. Our major geographic area of concentration is throughout the United States, with a growing presence in Europe. Our company’s principal customers are individual investors, corporations, municipalities, and institutions. On January 3, 2017, the Company completed the acquisition of City Financial Corporation and its wholly owned subsidiary, City Securities Corporation (“City Securities”), an independent investment bank focused primarily on offering wealth management and public finance services across the Midwest. The acquisition was funded with cash from operations and common stock.
Basis Of Presentation	Basis of Presentation The consolidated financial statements include Stifel Financial Corp. and its wholly owned subsidiaries, principally Stifel, Nicolaus & Company, Incorporated (“Stifel”), Keefe, Bruyette & Woods, Inc., and Stifel Bank & Trust (“Stifel Bank”). All material intercompany balances and transactions have been eliminated. Unless otherwise indicated, the terms “we,” “us,” “our,” or “our company” in this report refer to Stifel Financial Corp. and its wholly owned subsidiaries. We have prepared the accompanying unaudited consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Pursuant to these rules and regulations, we have omitted certain information and footnote disclosures we normally include in our annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles. In management’s opinion, we have made all adjustments (consisting only of normal, recurring adjustments, except as otherwise noted) necessary to fairly present our financial position, results of operations and cash flows. Our interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and the notes thereto in our Annual Report on Form 10-K for the year ended December 31, 2016 on file with the SEC. Certain amounts from prior periods have been reclassified to conform to the current period’s presentation. During the first quarter of 2017, we adopted Accounting Standards Update (“ASU”) 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. Amounts previously reported for the quarter ended March 31, 2016 have been restated as required upon adoption of the ASU. See Note 2 for further discussion. There have been no material changes in our significant accounting policies, as compared to the significant accounting policies described in our Annual Report on Form 10-K for the year ended December 31, 2016, with the exception of the new guidance on stock-based compensation.
Recently Adopted Accounting Guidance	Recently Adopted Accounting Guidance Share-Based Payments In March 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-09, “Improvements to Employee Share-Based Payment Accounting” that requires an entity to record all excess tax benefits and tax deficiencies as an income tax benefit or expense in the income statement. The update no longer requires cash flows related to excess tax benefits to be presented as a financing activity separate from other income tax cash flows. The update also clarifies that all cash payments to taxing authorities made on an employee's behalf for withheld shares should be presented as a financing activity on the statement of cash flows and requires an entity to elect an accounting policy to either estimate the number of forfeitures or account for forfeitures when they occur. The guidance is effective for fiscal years beginning after December 15, 2016 (January 1, 2017 for our company). We adopted the guidance in the update on January 1, 2017, and during the three months ended March 31, 2017 recognized an excess tax benefit from stock-based compensation of $16.9 million in the provision for income taxes on the accompanying consolidated statements of operations (adopted prospectively). Excess tax benefits from stock based compensation are now classified in operating activities on the accompanying consolidated statement of cash flows instead of being separately stated in financing activities for the three months ended March 31, 2017 (adopted prospectively). Cash paid to a tax authority by our company when withholding shares from an employee’s award for tax-withholding purposes are now classified as a financing activity in the accompanying consolidated statement of cash flows (adopted retrospectively). We reclassified $36.0 million from operating activities to financing activities in the accompanying consolidated statement of cash flows for the three months ended March 31, 2016 pertaining to shares withheld from employee awards for tax withholding purposes. Following the adoption of ASU 2016-09, we will continue to estimate forfeitures.
Recently Issued Accounting Guidance	Recently Issued Accounting Guidance Goodwill Impairment Testing In January 2017, the FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which simplifies the subsequent measurement of goodwill and eliminates Step 2 from the goodwill impairment test. Under the new guidance, the annual, or interim, goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount, and an impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. In addition, income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. The amendments also eliminate the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The amendments are to be applied on a prospective basis. The guidance is effective for annual or any interim impairment tests in fiscal years beginning after December 15, 2019 (January 1, 2020 for our company). Early adoption is permitted. We are currently evaluating the effect that the new guidance will have on our consolidated financial statements. Statement of Cash Flow – Restricted Cash In November 2016, the FASB issued ASU 2016-18, "Statement of Cash Flow - Restricted Cash," which adds or clarifies guidance on the classification and presentation of restricted cash in the statement of cash flows. The ASU is effective for the fiscal year beginning after December 15, 2017 (January 1, 2018 for our Company). Early adoption is permitted. We are currently evaluating the effect that the new guidance will have on our consolidated financial statements. Financial Instruments – Credit Losses In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” For trade receivables, loans, and held-to-maturity debt securities, the current probable loss recognition methodology is being replaced by an expected credit loss model. For available-for-sale debt securities, the recognition model on credit losses is generally unchanged, except the losses will be presented as an adjustable allowance. The guidance is effective for fiscal years beginning after December 15, 2019 (January 1, 2020 for our Company), including interim periods within that reporting period. Early adoption is permitted for annual periods beginning after December 15, 2018. We have been closely monitoring FASB activity related to the new standard. During the second half of 2016, we began developing a plan regarding the evaluation of the potential changes from adopting the new standard on our future financial reporting and disclosures. We expect to adopt the requirements of the new standard in the first quarter of 2020. Leases In February 2016, the FASB issued ASU No. 2016-02, “Leases” that requires lessees to recognize a right-of-use asset and a lease liability on the balance sheet for all leases with the exception of short-term leases. For lessees, leases will continue to be classified as either operating or finance leases in the income statement. Lessor accounting is similar to the current model but updated to align with certain changes to the lessee model. Lessors will continue to classify leases as operating, direct financing or sales-type leases. The new standard must be adopted using a modified retrospective transition and requires application of the new guidance at the beginning of the earliest comparative period presented. The guidance is effective for fiscal years beginning after December 15, 2018 (January 1, 2019 for our company). Early adoption is permitted. We have been closely monitoring FASB activity related to the new standard. During the second half of 2016, we began developing a plan regarding the evaluation of the potential changes from adopting the new standard on our future financial reporting and disclosures. We also made progress on our contract reviews and detailed policy drafting. Based on our evaluation, we expect to adopt the requirements of the new standard in the first quarter of 2019 and anticipate using the modified retrospective approach. Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities” that will change the income statement impact of equity investments held by an entity, and the recognition of changes in fair value of financial liabilities when the fair value option is elected. The guidance is effective for fiscal years beginning after December 15, 2017 (January 1, 2018 for our company). We are currently evaluating the effect that the new guidance will have on our consolidated financial statements. Revenue Recognition In April 2016, the FASB issued ASU No. 2016-10, “Identifying Performance Obligations and Licensing” that amends the revenue guidance in ASU 2014-09 on identifying performance obligations. The effective date of the new guidance will coincide with ASU 2014-09 during the first quarter 2018. We are currently evaluating the effect that the new guidance will have on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-08, “Principal versus Agent Considerations (Reporting Revenue Gross versus Net)” (“ASU 2016-08”) that amends the principal versus agent guidance in ASU 2014-09. ASU 2016-08 clarifies that the analysis must focus on whether the entity has control of the goods or services before they are transferred to the customer. ASU 2016-08 also provides additional guidance about how to apply the control principle when services are provided and when goods or services are combined with other goods or services. The effective date of the standard for the Company will coincide with ASU 2014-09 during the first quarter 2018. We are currently evaluating the effect that the new guidance will have on our consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers (Topic 606)," ("ASU 2014-09") that supersedes current revenue recognition guidance, including most industry-specific guidance. ASU 2014-09 requires a company to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services. The guidance also requires additional disclosures regarding the nature, amount, timing and uncertainty of revenue that is recognized. The FASB has approved a one year deferral of this standard, and this pronouncement is now effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period and is to be applied using one of two retrospective application methods, with early application not permitted. We are currently evaluating the impact the new guidance will have on our consolidated financial statements. We have been closely monitoring FASB activity related to the new standard. During the second half of 2016, we began developing a plan regarding the evaluation of the potential changes from adopting the new standard on our future financial reporting and disclosures. We also made progress on our contract reviews and detailed policy drafting. Based on our evaluation, we expect to adopt the requirements of the new standard in the first quarter of 2018 and anticipate using the modified retrospective approach.