Salary Deferral Plans	12 Months Ended
Dec. 31, 2017
Deferred Compensation Arrangements [Abstract]
Salary Deferral Plans	Note 14. Salary Deferral Plans Pinnacle Financial has a 401(k) retirement plan (the 401k Plan) covering all employees who elect to participate, subject to certain eligibility requirements. The Plan allows employees to defer up to 50% of their salary subject to regulatory limitations with Pinnacle Financial matching 100% of the first 4% of employee self-directed contributions during 2017, 2016, and 2015. Pinnacle Financial's expense associated with the matching component of the plan for each of the years in the three-year period ended December 31, 2017 was approximately $5.9 million, $4.0 million and $2.7 million, respectively, and is included in the accompanying consolidated statements of operations in salaries and employee benefits expense. Pinnacle Financial assumed nonqualified noncontributory supplemental retirement agreements (the Cavalry SRAs) for certain directors and executive officers of Cavalry Bancorp, Inc. (Cavalry), which Pinnacle Financial acquired in 2006. During 2007, Pinnacle Financial offered a settlement to all participants in the Cavalry SRAs with eleven participants accepting the settlement. One individual remains as a participant in the Cavalry SRAs. At December 31, 2017, 2016 and 2015, included in other liabilities is $1.0 million, $1.2 million, and $1.3 million, respectively, which represents the net present value of the future obligation owed the remaining participant in the Cavalry SRAs using a discount rate of 5% at December 31, 2017, 2016 and 2015. In conjunction with other completed acquisitions, Pinnacle has assumed $33.0 million in liabilities associated with existing supplemental executive retirement plans, of which $20.0 million have been fully funded with rabbi trusts. The remaining amounts that are not funded are included in other liabilities in the accompanying consolidated balance sheets.

Note 14. Salary Deferral Plans

Pinnacle Financial has a 401(k) retirement plan (the 401k Plan) covering all employees who elect to participate, subject to certain eligibility requirements. The Plan allows employees to defer up to 50% of their salary subject to regulatory limitations with Pinnacle Financial matching 100% of the first 4% of employee self-directed contributions during 2017, 2016, and 2015. Pinnacle Financial's expense associated with the matching component of the plan for each of the years in the three-year period ended December 31, 2017 was approximately $5.9 million, $4.0 million and $2.7 million, respectively, and is included in the accompanying consolidated statements of operations in salaries and employee benefits expense.

Pinnacle Financial assumed nonqualified noncontributory supplemental retirement agreements (the Cavalry SRAs) for certain directors and executive officers of Cavalry Bancorp, Inc. (Cavalry), which Pinnacle Financial acquired in 2006. During 2007, Pinnacle Financial offered a settlement to all participants in the Cavalry SRAs with eleven participants accepting the settlement. One individual remains as a participant in the Cavalry SRAs. At December 31, 2017, 2016 and 2015, included in other liabilities is $1.0 million, $1.2 million, and $1.3 million, respectively, which represents the net present value of the future obligation owed the remaining participant in the Cavalry SRAs using a discount rate of 5% at December 31, 2017, 2016 and 2015.

In conjunction with other completed acquisitions, Pinnacle has assumed $33.0 million in liabilities associated with existing supplemental executive retirement plans, of which $20.0 million have been fully funded with rabbi trusts. The remaining amounts that are not funded are included in other liabilities in the accompanying consolidated balance sheets.