Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying unaudited consolidated financial statements as of and for the period ended March 31, 2017 include CapStar Financial Holdings, Inc. and its wholly owned subsidiary, CapStar Bank (the “Bank”, together referred to as the “Company”). Significant intercompany transactions and accounts are eliminated in consolidation. On February 5, 2016, CapStar Financial Holdings, Inc. acquired all of the Bank’s issued and outstanding shares of common stock, preferred stock, common stock options and warrants, and the Bank became the wholly owned subsidiary of CapStar Financial Holdings, Inc. The accompanying unaudited consolidated financial statements have been prepared in accordance with instructions to Form 10-Q and do not include all information and footnotes required by U.S. generally accepted accounting principles (“U.S. GAAP”) for complete financial statements. All adjustments consisting of normally recurring accruals that, in the opinion of management, are necessary for a fair presentation of the financial position and results of operations for the periods presented have been included. These unaudited consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements and related notes appearing in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. Initial Public Offering On September 21, 2016, the Securities and Exchange Commission (“SEC”) declared effective our registration statement on Form S-1 registering the shares of our common stock. On September 27, 2016, we completed the initial public offering of 2,972,750 shares of our common stock. Of the 2,972,750 shares sold, 1,688,049 shares were sold by us and 1,284,701 shares were sold by certain selling shareholders. Of the 1,284,701 shares sold by certain selling shareholders, 731,707 were from preferred shares converted to common shares and 79,166 from the cashless exercise of 250,000 common share warrants. We received net proceeds of approximately $21.9 million from the offering, after deducting the underwriting discounts and commissions and estimated offering expenses. We did not receive any proceeds from the sale of shares by the selling shareholders. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan and lease losses, determination of impairment of intangible assets, including goodwill, the valuation of our investment portfolio, deferred tax assets and estimated liabilities. There have been no significant changes to the Company’s critical accounting policies as disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016. Subsequent Events Accounting Standards Codification (“ASC”) 855, Subsequent Events, establishes general standards of accounting for and disclosure of events that occur after the balance sheet date but before financial statements are issued. The Company evaluated all events or transactions that occurred after March 31, 2017 through the date of the issued financial statements.

NOTE 1 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The accompanying unaudited consolidated financial statements as of and for the period ended March 31, 2017 include CapStar Financial Holdings, Inc. and its wholly owned subsidiary, CapStar Bank (the “Bank”, together referred to as the “Company”). Significant intercompany transactions and accounts are eliminated in consolidation. On February 5, 2016, CapStar Financial Holdings, Inc. acquired all of the Bank’s issued and outstanding shares of common stock, preferred stock, common stock options and warrants, and the Bank became the wholly owned subsidiary of CapStar Financial Holdings, Inc.

The accompanying unaudited consolidated financial statements have been prepared in accordance with instructions to Form 10-Q and do not include all information and footnotes required by U.S. generally accepted accounting principles (“U.S. GAAP”) for complete financial statements. All adjustments consisting of normally recurring accruals that, in the opinion of management, are necessary for a fair presentation of the financial position and results of operations for the periods presented have been included. These unaudited consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements and related notes appearing in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016.

Initial Public Offering

On September 21, 2016, the Securities and Exchange Commission (“SEC”) declared effective our registration statement on Form S-1 registering the shares of our common stock. On September 27, 2016, we completed the initial public offering of 2,972,750 shares of our common stock. Of the 2,972,750 shares sold, 1,688,049 shares were sold by us and 1,284,701 shares were sold by certain selling shareholders. Of the 1,284,701 shares sold by certain selling shareholders, 731,707 were from preferred shares converted to common shares and 79,166 from the cashless exercise of 250,000 common share warrants. We received net proceeds of approximately $21.9 million from the offering, after deducting the underwriting discounts and commissions and estimated offering expenses. We did not receive any proceeds from the sale of shares by the selling shareholders.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan and lease losses, determination of impairment of intangible assets, including goodwill, the valuation of our investment portfolio, deferred tax assets and estimated liabilities. There have been no significant changes to the Company’s critical accounting policies as disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016.

Subsequent Events

Accounting Standards Codification (“ASC”) 855, Subsequent Events, establishes general standards of accounting for and disclosure of events that occur after the balance sheet date but before financial statements are issued. The Company evaluated all events or transactions that occurred after March 31, 2017 through the date of the issued financial statements.