Fair Value of Financial Instruments (Details) (USD $)											3 Months Ended																								3 Months Ended		12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Carrying Amount / Notional Amount [Member]		Dec. 31, 2012 Carrying Amount / Notional Amount [Member]		Mar. 31, 2013 Estimated Fair Value [Member]		Dec. 31, 2012 Estimated Fair Value [Member]		Mar. 31, 2013 Other Liabilities [Member]	Mar. 31, 2012 Other Liabilities [Member]	Mar. 31, 2013 Other Assets [Member]	Mar. 31, 2012 Other Assets [Member]	Mar. 31, 2013 Quoted Market Prices in an Active Market (Level 1) [Member]		Dec. 31, 2012 Quoted Market Prices in an Active Market (Level 1) [Member]		Mar. 31, 2013 Models with Significant Observable Market Parameters (Level 2) [Member]		Dec. 31, 2012 Models with Significant Observable Market Parameters (Level 2) [Member]		Mar. 31, 2013 Models with Significant Unobservable Market Parameters (Level 3) [Member]		Dec. 31, 2012 Models with Significant Unobservable Market Parameters (Level 3) [Member]		Mar. 31, 2013 Recurring [Member]	Dec. 31, 2012 Recurring [Member]	Mar. 31, 2013 Recurring [Member] Quoted Market Prices in an Active Market (Level 1) [Member]	Dec. 31, 2012 Recurring [Member] Quoted Market Prices in an Active Market (Level 1) [Member]	Mar. 31, 2013 Recurring [Member] Models with Significant Observable Market Parameters (Level 2) [Member]	Dec. 31, 2012 Recurring [Member] Models with Significant Observable Market Parameters (Level 2) [Member]	Mar. 31, 2013 Recurring [Member] Models with Significant Unobservable Market Parameters (Level 3) [Member]	Dec. 31, 2012 Recurring [Member] Models with Significant Unobservable Market Parameters (Level 3) [Member]	Mar. 31, 2013 Nonrecurring [Member]		Dec. 31, 2012 Nonrecurring [Member]		Mar. 31, 2013 Nonrecurring [Member] Quoted Market Prices in an Active Market (Level 1) [Member]		Dec. 31, 2012 Nonrecurring [Member] Quoted Market Prices in an Active Market (Level 1) [Member]		Mar. 31, 2013 Nonrecurring [Member] Models with Significant Observable Market Parameters (Level 2) [Member]		Dec. 31, 2012 Nonrecurring [Member] Models with Significant Observable Market Parameters (Level 2) [Member]		Mar. 31, 2013 Nonrecurring [Member] Models with Significant Unobservable Market Parameters (Level 3) [Member]		Dec. 31, 2012 Nonrecurring [Member] Models with Significant Unobservable Market Parameters (Level 3) [Member]
Investment securities available for sale [Abstract]
U.S. government agency securities																											$ 138,244,000	$ 110,452,000	$ 0	$ 0	$ 138,244,000	$ 110,452,000	$ 0	$ 0
Mortgage-backed securities																											371,857,000	375,651,000	0	0	371,857,000	375,651,000	0	0
State and municipal securities																											145,107,000	191,727,000	0	0	145,107,000	191,727,000	0	0
Agency- backed securities																											17,358,000	17,352,000	0		17,358,000	17,352,000	0
Corporate notes and other																											10,979,000	11,396,000	0	0	10,979,000	11,396,000	0	0
Total investment securities available-for-sale																											683,545,000	706,578,000	0	0	683,545,000	706,578,000	0	0
Alternative investments																											4,663,000	4,214,000	0	0	0	0	4,663,000	4,214,000
Other assets																											16,131,000	16,599,000	0	0	15,709,000	16,132,000	422,000	467,000
Total assets at fair value																											704,339,000	727,391,000	0	0	699,254,000	722,710,000	5,085,000	4,681,000
Liabilities at fair value [Abstract]
Other liabilities																											16,000,000	16,366,000	0	0	16,000,000	16,366,000	0	0
Total liabilities at fair value																											16,000,000	16,366,000	0	0	16,000,000	16,366,000	0	0
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned																																			16,802,000		18,580,000		0		0		0		0		16,802,000		18,580,000
Nonaccrual loans, net																																			20,088,000	[1]	21,059,000	[1]	0	[1]	0	[1]	0	[1]	0	[1]	20,088,000	[1]	21,059,000	[1]
Total																																			36,890,000		39,639,000		0		0		0		0		36,890,000		39,639,000
Valuation allowance of impaired loans	1,700,000	1,800,000
Gain (losses) on Other real estate owned																																			218,000		(5,428,000)
Gain (losses) on Impaired loans, net																																			2,192,000	[1]	(4,745,000)	[1]
Total gains (losses)																																			2,410,000		(10,173,000)
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, January 1											0	0	4,681,000	3,400,000
Total net realized (losses) gains included in income											0	0	100,000	115,000
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at March 31											0	0	0	0
Purchases, issuances and settlements, net											0	0	304,000	71,000
Transfers out of Level 3											0	0	0	0
Fair value, March 31											0	0	5,085,000	3,586,000
Total realized (losses) gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31											0	0	100,000	115,000
Financial assets [Abstract]
Securities held-to-maturity	40,377,000	583,000	40,459,000		575,000		40,377,000	[2]	583,000	[2]					0		0		40,377,000		583,000		0		0
Loans, net			3,702,952,000		3,642,744,000		3,408,914,000	[2]	3,358,435,000	[2]					0		0		0		0		3,408,914,000		3,358,435,000
Mortgage loans held-for-sale			30,327,000		41,195,000		30,999,000		42,425,000	[2]					0		0		30,999,000		42,425,000		0		0
Financial liabilities [Abstract]
Deposits and securities sold under agreements to repurchase			4,031,994,000		4,129,855,000		3,988,176,000	[2]	4,084,314,000	[2]					0		0		0		0		3,988,176,000		4,084,314,000
Federal Home Loan Bank advances			200,796,000		75,850,000		200,526,000	[2]	76,350,000	[2]					0		0		0		0		200,526,000		76,350,000
Subordinated debt and other borrowings			105,533,000		106,158,000		80,229,000	[2]	83,862,000	[2]					0		0		0		0		80,229,000		83,862,000
Off-balance sheet instruments [Abstract]
Commitments to extend credit			1,118,203,000	[3]	1,030,723,000	[3]	2,605,000	[2],[3]	1,594,000	[2],[3]					0	[3]	0	[3]	0	[3]	0	[3]	2,605,000	[3]	1,594,000	[3]
Standby letters of credit	$ 39,942,214	$ 48,252,519	$ 68,554,000	[4]	$ 74,679,000	[4]	$ 266,000	[2],[4]	$ 304,000	[2],[4]					$ 0	[4]	$ 0	[4]	$ 0	[4]	$ 0	[4]	$ 266,000	[4]	$ 304,000	[4]

[1] Amount is net of a valuation allowance of $1.7 million at March 31, 2013 and $1.8 million at December 31, 2012 as required by ASC 310-10, "Receivables."

[2] 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.

[3] 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 March 31, 2013 and December 31, 2012, Pinnacle Financial included in other liabilities $2.9 million and $1.6 million, respectively, representing the inherent risks associated with these off-balance sheet commitments.

[4] At March 31, 2013 and December 31, 2012, the fair value of Pinnacle Financial's standby letters of credit was $266,000 and $304,000, respectively. This amount represents the unamortized fee associated with these standby letters of credit 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.