Income Taxes	3 Months Ended
Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Note 5. Income Taxes ASC 740, Income Taxes, defines the threshold for recognizing the benefits of tax return positions in the financial statements as "more-likely-than-not" to be sustained by the taxing authority. This section also provides guidance on the derecognition, measurement and classification of income tax uncertainties, along with any related interest and penalties, and includes guidance concerning accounting for income tax uncertainties in interim periods. The unrecognized tax benefit related to uncertain tax positions related to state income tax filings was $5.1 million at March 31, 2019 compared to $2.8 million at March 31, 2018. No change was recorded to the unrecognized tax benefit related to uncertain tax positions in each of the three month periods ended March 31, 2019 and 2018. Pinnacle Financial's policy is to recognize interest and/or penalties related to income tax matters in income tax expense. For both the three months ended March 31, 2019 and 2018, respectively, there were no interest and penalties recorded in the income statement. Pinnacle Financial's effective tax rate for the three months ended March 31, 2019 was 19.7% compared to 19.0% for the three months ended March 31, 2018. The difference between the effective tax rate and the federal and state income tax statutory rate of 26.14% at March 31, 2019 and 2018 is primarily due to investments in bank qualified municipal securities, tax benefits of Pinnacle Bank's real estate investment trust subsidiary, participation in the Tennessee Community Investment Tax Credit (CITC) program, and tax benefits associated with share-based compensation, bank-owned life insurance and our captive insurance subsidiary, offset in part by the limitation on deductibility of meals and entertainment expense, non-deductible executive compensation and non-deductible FDIC premiums. Also impacting income tax expense for the three months ended March 31, 2019 were excess windfall tax benefits of $769,000 recognized upon the lapse of restrictions on stock awards and stock options exercises, compared to $2.7 million for the three months ended March 31, 2018.

Note 5. Income Taxes

ASC 740, Income Taxes, defines the threshold for recognizing the benefits of tax return positions in the financial statements as "more-likely-than-not" to be sustained by the taxing authority. This section also provides guidance on the derecognition, measurement and classification of income tax uncertainties, along with any related interest and penalties, and includes guidance concerning accounting for income tax uncertainties in interim periods.

The unrecognized tax benefit related to uncertain tax positions related to state income tax filings was $5.1 million at March 31, 2019 compared to $2.8 million at March 31, 2018. No change was recorded to the unrecognized tax benefit related to uncertain tax positions in each of the three month periods ended March 31, 2019 and 2018.

Pinnacle Financial's policy is to recognize interest and/or penalties related to income tax matters in income tax expense. For both the three months ended March 31, 2019 and 2018, respectively, there were no interest and penalties recorded in the income statement.

Pinnacle Financial's effective tax rate for the three months ended March 31, 2019 was 19.7% compared to 19.0% for the three months ended March 31, 2018. The difference between the effective tax rate and the federal and state income tax statutory rate of 26.14% at March 31, 2019 and 2018 is primarily due to investments in bank qualified municipal securities, tax benefits of Pinnacle Bank's real estate investment trust subsidiary, participation in the Tennessee Community Investment Tax Credit (CITC) program, and tax benefits associated with share-based compensation, bank-owned life insurance and our captive insurance subsidiary, offset in part by the limitation on deductibility of meals and entertainment expense, non-deductible executive compensation and non-deductible FDIC premiums. Also impacting income tax expense for the three months ended March 31, 2019 were excess windfall tax benefits of $769,000 recognized upon the lapse of restrictions on stock awards and stock options exercises, compared to $2.7 million for the three months ended March 31, 2018.