Stock Options, Stock Appreciation Rights and Restricted Shares (Details)		3 Months Ended			6 Months Ended	9 Months Ended			12 Months Ended
		Sep. 30, 2015 USD ($) $ / shares shares		Sep. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) $ / shares shares	Sep. 30, 2015 USD ($) $ / shares shares		Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) $ / shares shares		Sep. 30, 2015 USD ($) Plan $ / shares shares	Dec. 31, 2014 $ / shares shares
Stock Options, Stock Appreciation Rights and Restricted Shares [Abstract]
Number of equity incentive plan | Plan											1
Restricted stock grants grouped by similar vesting criteria [Abstract]
Stock-based compensation expense | $						$ 5,305,028		$ 3,969,973
Stock Appreciation Rights (SARs) [Member]
Number [Roll Forward]
Outstanding, Ending Balance (in shares)		2,481				2,481					2,481
Exercised (in shares)	[1]					(1,230)
Outstanding, Ending Balance (in shares)		2,481				2,481
Aggregate intrinsic value [Abstract]
Stock appreciation rights converted to common stock (in shares)						537
Stock Option [Member]
Number [Roll Forward]
Outstanding, Ending Balance (in shares)		1,347,824				1,347,824					1,347,824
Outstanding, Ending Balance (in shares)		1,347,824				1,347,824
Restricted Share [Member]
Number [Roll Forward]
Unvested, beginning of period (in shares)					849,198	849,198
Shares awarded (in shares)						222,335
Conversion of restricted share units to restricted share awards (in shares)						43,711
Restrictions lapsed and shares released to associates/directors (in shares)						(234,607)
Shares forfeited (in shares)	[2]					(14,850)
Unvested, end of period (in shares)		865,787				865,787			849,198
Grant date weighted average cost [Roll Forward]
Unvested, beginning of period (in dollars per share) | $ / shares					$ 24.26	$ 24.26
Shares awarded (in dollars per share) | $ / shares						45.41
Conversion of restricted share units to restricted share awards (in dollars per share) | $ / shares						34.50
Restrictions lapsed and shares released to associates/directors (in dollars per share) | $ / shares						23.04
Shares forfeited (in dollars per share) | $ / shares	[2]					28.63
Unvested, end of period (in dollars per share) | $ / shares		$ 30.47				$ 30.47			$ 24.26
Shares forfeited due to failure to meet performance targets (in shares)						0
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						222,335
Shares forfeited by participants (in shares)	[2]					14,850
Shares Unvested (in shares)		865,787			849,198	849,198			849,198		865,787	849,198
Stock-based compensation expense | $		$ 1,600,000		$ 1,300,000		$ 4,300,000		3,700,000
Restricted share units, awarded (in shares)						222,335
Restricted Share [Member] | CapitalMark Bank & Trust [Member]
Number [Roll Forward]
Shares awarded (in shares)						52,000
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						52,000
Restricted share units, awarded (in shares)						52,000
Restricted Share [Member] | Magna Bank [Member]
Number [Roll Forward]
Shares awarded (in shares)						40,000
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						40,000
Restricted share units, awarded (in shares)						40,000
Common Stock Options and Stock Appreciation Rights [Member]
Number [Roll Forward]
Outstanding, Ending Balance (in shares)		1,350,305				1,350,305			698,488		1,350,305	698,488
Granted (in shares)						0
CapitalMark Options issued upon acquisition						858,143
Exercised (in shares)						(205,091)
Forfeited (in shares)						(5)
Outstanding, Ending Balance (in shares)		1,350,305				1,350,305			698,488
Outstanding and expected to vest (in shares)											1,350,305
Weighted average exercise price [Abstract]
Outstanding, Beginning Balance (in dollars per share) | $ / shares					$ 26.89	$ 26.89
Outstanding, Ending Balance (in dollars per share) | $ / shares		$ 21.24				$ 21.24			$ 26.89
Options exercisable (in dollars per share) | $ / shares											$ 21.24
Weighted average contractual remaining term [Abstract]
Outstanding, beginning of period						2 years 10 months 24 days			1 year 10 months 24 days
Outstanding, end of period						2 years 10 months 24 days			1 year 10 months 24 days
Outstanding and expected to vest						2 years 10 months 24 days
Aggregate intrinsic value [Abstract]
Outstanding, beginning of period | $	[3]				$ 9,071,000	$ 9,071,000
Outstanding, end of period | $		$ 36,610,000	[4]			$ 36,610,000	[4]		$ 9,071,000	[3]
Outstanding and expected to vest | $	[4]										$ 36,610,000
Quoted closing price of common stock (in dollars per share) | $ / shares											$ 49.41	$ 39.54
Number of awards used in aggregate intrinsic value (in shares)											1,350,305	698,488
Unrecognized compensation cost related to unvested stock options granted | $											$ 0
Time Based Awards [Member]
Number [Roll Forward]
Shares awarded (in shares)	[5]					16,605
Shares forfeited (in shares)	[5],[6]					0
Unvested, end of period (in shares)	[5]	16,605				16,605
Restricted stock grants grouped by similar vesting criteria [Abstract]
Group	[5],[7]					Leadership team
Vesting Period in years	[5]					5 years
Shares awarded (in shares)	[5]					16,605
Restrictions lapsed and shares released to participants (in shares)	[5]					0
Shares forfeited by participants (in shares)	[5],[6]					0
Shares Unvested (in shares)	[5]	16,605				16,605					16,605
Restricted share units, awarded (in shares)	[5]					16,605
Time Based Awards [Member] | CapitalMark Bank & Trust [Member]
Number [Roll Forward]
Shares awarded (in shares)						41,000
Grant date weighted average cost [Roll Forward]
Vesting period						5 years
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						41,000
Restricted share units, awarded (in shares)						41,000
Time Based Awards [Member] | Magna Bank [Member]
Number [Roll Forward]
Shares awarded (in shares)						23,000
Grant date weighted average cost [Roll Forward]
Vesting period						5 years
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						23,000
Restricted share units, awarded (in shares)						23,000
Time Based Awards [Member] | Associates [Member]
Number [Roll Forward]
Shares awarded (in shares)	[8]					181,359
Shares forfeited (in shares)	[6],[8]					(3,396)
Unvested, end of period (in shares)	[8]	177,950				177,950
Restricted stock grants grouped by similar vesting criteria [Abstract]
Group	[7],[8]					Associates
Vesting Period in years	[8]					5 years
Shares awarded (in shares)	[8]					181,359
Restrictions lapsed and shares released to participants (in shares)	[8]					13
Shares forfeited by participants (in shares)	[6],[8]					3,396
Shares Unvested (in shares)	[8]	177,950				177,950					177,950
Restricted share units, awarded (in shares)	[8]					181,359
Performance Based Awards [Member] | CapitalMark Bank & Trust [Member]
Grant date weighted average cost [Roll Forward]
Vesting period						3 years
Performance Based Awards [Member] | Magna Bank [Member]
Grant date weighted average cost [Roll Forward]
Vesting period						5 years
Performance Based Awards [Member] | Leadership Team [Member]
Number [Roll Forward]
Shares awarded (in shares)	[9]					43,711
Shares forfeited (in shares)	[6],[9]					0
Unvested, end of period (in shares)	[9]	43,711				43,711
Restricted stock grants grouped by similar vesting criteria [Abstract]
Group	[7],[9]					Leadership team
Vesting Period in years	[9]					5 years
Shares awarded (in shares)	[9]					43,711
Restrictions lapsed and shares released to participants (in shares)	[9]					0
Shares forfeited by participants (in shares)	[6],[9]					0
Shares Unvested (in shares)	[9]	43,711				43,711					43,711
Restricted share units, awarded (in shares)	[9]					43,711
Performance Based Awards [Member] | Leadership Team - CapitalMark [Member]
Number [Roll Forward]
Shares awarded (in shares)	[10]					11,302
Shares forfeited (in shares)	[6],[10]					0
Unvested, end of period (in shares)	[10]	11,302				11,302
Restricted stock grants grouped by similar vesting criteria [Abstract]
Group	[7],[10]					Leadership team
Vesting Period in years	[10]					3 years
Shares awarded (in shares)	[10]					11,302
Restrictions lapsed and shares released to participants (in shares)	[10]					0
Shares forfeited by participants (in shares)	[6],[10]					0
Shares Unvested (in shares)	[10]	11,302				11,302					11,302
Restricted share units, awarded (in shares)	[10]					11,302
Outside Director Awards [Member]
Number [Roll Forward]
Shares awarded (in shares)	[11]					13,069
Shares forfeited (in shares)	[6],[11]					0
Unvested, end of period (in shares)	[11]	12,164				12,164
Restricted stock grants grouped by similar vesting criteria [Abstract]
Group	[7],[11]					Outside directors
Vesting Period in years	[11]					1 year
Shares awarded (in shares)	[11]					13,069
Restrictions lapsed and shares released to participants (in shares)	[11]					905
Shares forfeited by participants (in shares)	[6],[11]					0
Shares Unvested (in shares)	[11]	12,164				12,164					12,164
Restricted share units, awarded (in shares)	[11]					13,069
2015 Restricted Share Units [Member]
Restricted stock grants grouped by similar vesting criteria [Abstract]
Stock-based compensation expense | $		$ 143,000.00		0		$ 389,000.00		0
2015 Restricted Share Units [Member] | Senior Executive Officers [Member] | Minimum [Member]
Number [Roll Forward]
Shares awarded (in shares)						58,200
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						58,200
Restricted share units, awarded (in shares)						58,200
2015 Restricted Share Units [Member] | Senior Executive Officers [Member] | Maximum [Member]
Number [Roll Forward]
Shares awarded (in shares)						101,850
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						101,850
Restricted share units, awarded (in shares)						101,850
2015 Restricted Share Units [Member] | Leadership Team [Member]
Number [Roll Forward]
Shares awarded (in shares)						28,378
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						28,378
Restricted share units, awarded (in shares)						28,378
2014 Restricted Share Unit [Member]
Number [Roll Forward]
Shares awarded (in shares)					43,711
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)					43,711
Stock-based compensation expense | $		$ 193,000.00		$ 92,000.00		$ 582,000.00		$ 215,000.00
Restricted share units, awarded (in shares)					43,711
2014 Restricted Share Unit [Member] | Senior Executive Officers [Member] | Minimum [Member]
Number [Roll Forward]
Shares awarded (in shares)						58,404
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						58,404
Restricted share units, awarded (in shares)						58,404
2014 Restricted Share Unit [Member] | Senior Executive Officers [Member] | Maximum [Member]
Number [Roll Forward]
Shares awarded (in shares)						102,209
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						102,209
Restricted share units, awarded (in shares)						102,209
2014 Restricted Share Unit [Member] | Leadership Team [Member]
Number [Roll Forward]
Shares awarded (in shares)						29,087
Restricted stock grants grouped by similar vesting criteria [Abstract]
Shares awarded (in shares)						29,087
Restricted share units, awarded (in shares)						29,087
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuances (in shares)											1,100,000

[1] 1,230 SARS were converted into 537 common shares upon exercise.

[2] Represents shares forfeited due to employee termination and/or retirement. No shares were forfeited due to failure to meet performance targets.

[3] The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the quoted closing price of Pinnacle Financial common stock of $39.54 per common share at December 31, 2014 for the approximately 698,488 options and stock appreciation rights that were in-the-money at December 31, 2014.

[4] The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the quoted closing price of Pinnacle Financial common stock of $49.41 per common share at September 30, 2015 for the approximately 1,350,305 options and stock appreciation rights that were in-the-money at September 30, 2015.

[5] These shares were awarded to individuals joining the leadership team upon acquisition of Magna. The forfeiture restrictions on these restricted share awards lapse in equal installments on the anniversary date of the grant.

[6] These shares represent forfeitures resulting from recipients for whom employment terminated during the year-to-date period ended September 30, 2015. Any dividends paid on shares for which the forfeiture restrictions do not lapse will be recouped by the Company at the time of termination.

[7] Groups include employees (referred to as associates above), the leadership team which includes our named executive officers and other key senior leadership members, and outside directors. When 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 to pay the applicable income taxes associated with the award. For time-based restricted share awards, dividends paid on shares for which the forfeiture restrictions do not lapse will be recouped by the Company at the time of termination. For performance-based awards, dividends are placed into escrow until the forfeiture restrictions on such shares lapse.

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

[9] The forfeiture restrictions on these restricted share awards lapse in separate equal installments should Pinnacle Financial achieve certain earnings and soundness targets over each year of the subsequent vesting period.

[10] These shares were awarded to individuals joining the leadership team upon the acquisition of CapitalMark. The forfeiture restrictions on these restricted share awards lapse in separate equal installments should Pinnacle Financial achieve certain earnings targets over each year of the vesting period and should the recipient thereafter remain employed by Pinnacle Financial for a subsequent vesting period.

[11] Restricted share awards are issued to the outside members of the board of directors in accordance with their board compensation plan. Restrictions lapse on the one year anniversary date of the award 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.