Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2018
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 September 30, 2018 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. 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, 2017. 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 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, 2017. 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 September 30, 2018 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 September 30, 2018 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.

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, 2017.

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 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, 2017.

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 September 30, 2018 through the date of the issued financial statements.