Fair Value of Financial Instruments (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Investment securities available for sale [Abstract]
Alternative investments	$ 4,214,000		$ 3,400,000
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Valuation allowance of impaired loans	1,800,000		4,400,000
Financial assets [Abstract]
Securities available-for-sale	706,578,000		894,962,000
Securities held-to-maturity	583,000		2,369,000
Alternative investments	4,214,000		3,400,000
Off-balance sheet instruments [Abstract]
Standby letters of credit	48,252,519		42,097,132
Carrying Amount / Notional Amount [Member]
Financial assets [Abstract]
Securities held-to-maturity	575,000		2,330,000
Loans, net	3,642,744,000		3,217,376,000
Mortgage loans held-for-sale	41,195,000		35,363,000
Financial liabilities [Abstract]
Deposits and securities sold under agreements to repurchase	4,129,855,000		3,785,931,000
Federal Home Loan Bank advances	75,850,000		226,069,000
Subordinated debt and other borrowings	106,158,000		97,476,000
Carrying Amount / Notional Amount [Member] | Standby Letters of Credit [Member]
Off-balance sheet instruments [Abstract]
Standby letters of credit	74,679,000	[1]	76,176,000	[1]
Carrying Amount / Notional Amount [Member] | Commitments to Extend Credit [Member]
Off-balance sheet instruments [Abstract]
Commitments to extend credit	1,030,723,000	[2]	937,084,000	[2]
Estimated Fair Value [Member]
Financial assets [Abstract]
Securities held-to-maturity	583,000	[3]	2,369,000	[3]
Loans, net	3,358,435,000		2,893,526,000	[3]
Mortgage loans held-for-sale	42,425,000	[3]	36,231,000	[3]
Financial liabilities [Abstract]
Deposits and securities sold under agreements to repurchase	4,084,314,000		3,752,490,000	[3]
Federal Home Loan Bank advances	76,350,000		226,460,000	[3]
Subordinated debt and other borrowings	83,862,000		72,030,000	[3]
Estimated Fair Value [Member] | Standby Letters of Credit [Member]
Off-balance sheet instruments [Abstract]
Standby letters of credit	304,000	[1],[3]	259,000	[1],[3]
Estimated Fair Value [Member] | Commitments to Extend Credit [Member]
Off-balance sheet instruments [Abstract]
Commitments to extend credit	1,594,000	[2],[3]	1,031,000	[2],[3]
Other Liabilities [Member]
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, January 1	0		0
Total net realized (losses) gains included in income	0		0
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at December 31	0		0
Purchases, issuances and settlements, net	0		0
Transfers out of Level 3	0		0
Fair value, December 31	0		0
Total realized (losses) gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31	0		0
Other Assets [Member]
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, January 1	3,899,000		3,238,000
Total net realized (losses) gains included in income	(101,000)		268,000
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at December 31	0		0
Purchases, issuances and settlements, net	883,000		393,000
Transfers out of Level 3	0		0
Fair value, December 31	4,681,000		3,899,000
Total realized (losses) gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31	(101,000)		268,000
Quoted Market Prices in an Active Market (Level 1) [Member]
Financial assets [Abstract]
Securities held-to-maturity	0		0
Loans, net	0		0
Mortgage loans held-for-sale	0		0
Financial liabilities [Abstract]
Deposits and securities sold under agreements to repurchase	0		0
Federal Home Loan Bank advances	0		0
Subordinated debt and other borrowings	0		0
Quoted Market Prices in an Active Market (Level 1) [Member] | Standby Letters of Credit [Member]
Off-balance sheet instruments [Abstract]
Standby letters of credit	0		0
Quoted Market Prices in an Active Market (Level 1) [Member] | Commitments to Extend Credit [Member]
Off-balance sheet instruments [Abstract]
Commitments to extend credit	0		0
Models with Significant Observable Market Parameters (Level 2) [Member]
Financial assets [Abstract]
Securities held-to-maturity	583,000		2,369,000
Loans, net	0		0
Mortgage loans held-for-sale	42,425,000		36,231,000
Financial liabilities [Abstract]
Deposits and securities sold under agreements to repurchase	0		3,752,490,000
Federal Home Loan Bank advances	0		0
Subordinated debt and other borrowings	0		72,030,000
Models with Significant Observable Market Parameters (Level 2) [Member] | Standby Letters of Credit [Member]
Off-balance sheet instruments [Abstract]
Standby letters of credit	0		0
Models with Significant Observable Market Parameters (Level 2) [Member] | Commitments to Extend Credit [Member]
Off-balance sheet instruments [Abstract]
Commitments to extend credit	0		0
Models with Significant Unobservable Market Parameters (Level 3) [Member]
Financial assets [Abstract]
Securities held-to-maturity	0		0
Loans, net	3,358,435,000		2,893,526,000
Mortgage loans held-for-sale	0		0
Financial liabilities [Abstract]
Deposits and securities sold under agreements to repurchase	4,084,314,000		0
Federal Home Loan Bank advances	76,350,000		226,460,000
Subordinated debt and other borrowings	83,862,000		0
Models with Significant Unobservable Market Parameters (Level 3) [Member] | Standby Letters of Credit [Member]
Off-balance sheet instruments [Abstract]
Standby letters of credit	304,000		259,000
Models with Significant Unobservable Market Parameters (Level 3) [Member] | Commitments to Extend Credit [Member]
Off-balance sheet instruments [Abstract]
Commitments to extend credit	1,594,000		1,031,000
Recurring [Member]
Investment securities available for sale [Abstract]
U.S. government agency securities	110,452,000		42,313,000
Mortgage-backed securities	375,651,000		645,567,000
State and municipal securities	191,727,000		195,952,000
Agency- backed securities	17,352,000
Corporate notes and other	11,396,000		11,130,000
Total investment securities available-for-sale	706,578,000		894,962,000
Alternative investments	4,214,000		3,400,000
Other assets	16,599,000		18,436,000
Total assets at fair value	727,391,000		916,798,000
Liabilities at fair value [Abstract]
Other liabilities	16,366,000		18,147,000
Total liabilities at fair value	16,366,000		18,147,000
Financial assets [Abstract]
Alternative investments	4,214,000		3,400,000
Recurring [Member] | Quoted Market Prices in an Active Market (Level 1) [Member]
Investment securities available for sale [Abstract]
U.S. government agency securities	0		0
Mortgage-backed securities	0		0
State and municipal securities	0		0
Corporate notes and other	0		0
Total investment securities available-for-sale	0		0
Alternative investments	0		0
Other assets	0		0
Total assets at fair value	0		0
Liabilities at fair value [Abstract]
Other liabilities	0		0
Total liabilities at fair value	0		0
Financial assets [Abstract]
Alternative investments	0		0
Recurring [Member] | Models with Significant Observable Market Parameters (Level 2) [Member]
Investment securities available for sale [Abstract]
U.S. government agency securities	110,452,000		42,313,000
Mortgage-backed securities	375,651,000		645,567,000
State and municipal securities	191,727,000		195,952,000
Agency- backed securities	17,352,000
Corporate notes and other	11,396,000		11,130,000
Total investment securities available-for-sale	706,578,000		894,962,000
Alternative investments	0		0
Other assets	16,132,000		17,937,000
Total assets at fair value	722,710,000		912,899,000
Liabilities at fair value [Abstract]
Other liabilities	16,366,000		18,147,000
Total liabilities at fair value	16,366,000		18,147,000
Financial assets [Abstract]
Alternative investments	0		0
Recurring [Member] | Models with Significant Unobservable Market Parameters (Level 3) [Member]
Investment securities available for sale [Abstract]
U.S. government agency securities	0		0
Mortgage-backed securities	0		0
State and municipal securities	0		0
Corporate notes and other	0		0
Total investment securities available-for-sale	0		0
Alternative investments	4,214,000		3,400,000
Other assets	467,000		499,000
Total assets at fair value	4,681,000		3,899,000
Liabilities at fair value [Abstract]
Other liabilities	0		0
Total liabilities at fair value	0		0
Financial assets [Abstract]
Alternative investments	4,214,000		3,400,000
Nonrecurring [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned	18,580,000		39,714,000
Nonperforming loans, net	21,059,000	[4]	43,415,000	[4]
Total	39,639,000		83,129,000
Gain (losses) on Other real estate owned	(5,428,000)		(6,890,000)
Gain (losses) on Impaired loans, net	(4,745,000)	[4]	(8,661,000)	[4]
Total gains (losses)	(10,173,000)		(15,551,000)
Nonrecurring [Member] | Quoted Market Prices in an Active Market (Level 1) [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned	0		0
Nonperforming loans, net	0	[4]	0	[4]
Total	0		0
Nonrecurring [Member] | Models with Significant Observable Market Parameters (Level 2) [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned	0		0
Nonperforming loans, net	0	[4]	0	[4]
Total	0		0
Nonrecurring [Member] | Models with Significant Unobservable Market Parameters (Level 3) [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned	18,580,000		39,714,000
Nonperforming loans, net	21,059,000	[4]	43,415,000	[4]
Total	$ 39,639,000		$ 83,129,000

[1] At December 31, 2012 and 2011, the fair value of Pinnacle Financial's standby letters of credit was $304,000 and $259,000, respectively. This amount represents the unamortized fee associated with these standby letters of credit, which were priced at market when issued, and is included in the consolidated balance sheet of Pinnacle Financial and is believed to approximate fair value. This fair value will decrease over time as the existing standby letters of credit approach their expiration dates.

[2] At the end of each quarter, Pinnacle Financial evaluates the inherent risks of the outstanding off-balance sheet commitments. In making this evaluation, Pinnacle Financial evaluates the credit worthiness of the borrower, the collateral supporting the commitments and any other factors similar to those used to evaluate the inherent risks of our loan portfolio. Additionally, Pinnacle Financial evaluates the probability that the outstanding commitment will eventually become a funded loan. As a result, at December 31, 2012 and 2011, Pinnacle Financial included in other liabilities $1.6 million and $1.0 million, respectively, representing the inherent risks associated with these off-balance sheet commitments.

[3] Estimated fair values are consistent with an exit-price concept. The assumptions used to estimate the fair values are intended to approximate those that a market-participant would realize in a hypothetical orderly transaction.

[4] Amount is net of a valuation allowance of $1.8 million at December 31, 2012 and $4.4 million at December 31, 2011 as required by ASC 310-10, "Receivables.