Stock Options and Restricted Shares - Restricted Shares Awarded (Details)	9 Months Ended
	Sep. 30, 2020 shares
Time Based Awards | Associates
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded	246,524	[1],[2]
Restrictions Lapsed and shares released to participants	116	[1],[2]
Shares Forfeited by participants	5,076	[1],[2],[3]
Shares Unvested	241,332	[1],[2]
Time Based Awards | Associates | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period in years	3 years
Time Based Awards | Associates | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period in years	5 years
Outside Director Awards | Outside directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period in years	1 year	[1],[4]
Shares awarded	18,525	[1],[4]
Restrictions Lapsed and shares released to participants	0	[1],[4]
Shares Forfeited by participants	0	[1],[3],[4]
Shares Unvested	18,525	[1],[4]

[1] Groups include employees (referred to as associates above) and outside directors. When the restricted shares are awarded, a participant receives voting rights and forfeitable dividend rights with respect to the shares, but is not able to transfer the shares until the restrictions have lapsed. Once the restrictions lapse, the participant is taxed on the value of the award and may elect to sell some shares (or have Pinnacle Financial withhold some shares) to pay the applicable income taxes associated with the award. Alternatively, the recipient can pay the withholding taxes in cash. For time-based vesting restricted share awards, dividends paid on shares for which the forfeiture restrictions do not lapse will be recouped by Pinnacle Financial at the time of termination. For performance-based vesting awards to Pinnacle Financial's directors, dividends are placed into escrow until the forfeiture restrictions on such shares lapse.

[2] The forfeiture restrictions on these restricted share awards lapse in equal annual installments on the anniversary date of the grant.

[3] These shares represent forfeitures resulting from recipients whose employment or board membership was terminated during the year-to-date period ended September 30, 2020. Any dividends paid on shares for which the forfeiture restrictions do not lapse will be recouped by Pinnacle Financial at the time of termination or will not be distributed from escrow, as applicable.

[4] Restricted share awards are issued to the outside members of the board of directors in accordance with their board compensation plan. Restrictions lapse on February 28, 2021 based on each individual board member meeting their attendance goals for the various board and board committee meetings to which each member was scheduled to attend.