Investments in Affiliated Companies and Subordinated Debt (Details) (USD $)	3 Months Ended												12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Aug. 05, 2008
Investments in and Advances to Affiliates [Line Items]
Subordinated term loan with regional bank	$ 106,158,292				$ 97,476,000								$ 106,158,292	$ 97,476,000		$ 15,000,000
Tenor of capital trust preferred securities													30 years
Investments in Trusts	2,476,000												2,476,000
Obligation reflected as subordinated debt	82,476,000												82,476,000
Maturity													Jun. 15, 2017
Assets threshold for Tier I capital treatment of Trust Preferred Securities	15,000,000,000												15,000,000,000
Proposed regulations for asset threshold treatment of Trust preferred securities as Tier I capital	15,000,000,000												15,000,000,000
Maximum number of consecutive quarters to defer the payment of interest													20
Combined Summary Balance Sheets [Abstract]
Liabilities	4,361,477,257				4,153,806,136								4,361,477,257	4,153,806,136
Total stockholders' equity	679,071,359				710,144,568				677,457,285				679,071,359	710,144,568	677,457,285
Total liabilities and stockholders' equity	5,040,548,616				4,863,950,704								5,040,548,616	4,863,950,704
Percentage of common security owned by parent (in hundredths)	100.00%												100.00%
Combined Summary Income Statements [Abstract]
Net income (loss)	11,730,000	11,349,000	10,440,000	8,365,000	7,760,000	26,101,000	6,372,000	3,505,000	3,796,000	2,091,000	(26,364,000)	(3,822,000)	41,883,881	43,737,367	(24,300,492)
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				710,144,568				677,457,285				701,020,181	710,144,568	677,457,285	701,020,181
Net income (loss)	11,730,000	11,349,000	10,440,000	8,365,000	7,760,000	26,101,000	6,372,000	3,505,000	3,796,000	2,091,000	(26,364,000)	(3,822,000)	41,883,881	43,737,367	(24,300,492)
Dividends [Abstract]
Ending Balances	679,071,359				710,144,568				677,457,285				679,071,359	710,144,568	677,457,285
Common Stock [Member]
Combined Summary Balance Sheets [Abstract]
Total stockholders' equity	34,696,597				34,354,960				33,870,380				34,696,597	34,354,960	33,870,380
Combined Summary Income Statements [Abstract]
Net income (loss)													0	0	0
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				34,354,960				33,870,380				33,029,719	34,354,960	33,870,380	33,029,719
Net income (loss)													0	0	0
Dividends [Abstract]
Ending Balances	34,696,597				34,354,960				33,870,380				34,696,597	34,354,960	33,870,380
Retained Earnings [Member]
Combined Summary Balance Sheets [Abstract]
Total stockholders' equity	87,386,689				49,783,584				12,996,202				87,386,689	49,783,584	12,996,202
Combined Summary Income Statements [Abstract]
Net income (loss)													41,883,881	43,737,367	(24,300,492)
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				49,783,584				12,996,202				43,372,743	49,783,584	12,996,202	43,372,743
Net income (loss)													41,883,881	43,737,367	(24,300,492)
Dividends [Abstract]
Ending Balances	87,386,689				49,783,584				12,996,202				87,386,689	49,783,584	12,996,202
Trust [Member]
Investments in and Advances to Affiliates [Line Items]
Common Securities	2,476,000				2,476,000								2,476,000	2,476,000
Combined Summary Balance Sheets [Abstract]
Asset - Investment in subordinated debentures issued by Pinnacle Financial	82,476,000				82,476,000								82,476,000	82,476,000
Liabilities	0				0								0	0
Stockholder's equity - Trust preferred securities	80,000,000				80,000,000								80,000,000	80,000,000
Common securities (100% owned by Pinnacle Financial)	2,476,000				2,476,000								2,476,000	2,476,000
Total stockholders' equity	82,476,000				82,476,000				82,476,000				82,476,000	82,476,000	82,476,000
Total liabilities and stockholders' equity	82,476,000				82,476,000								82,476,000	82,476,000
Combined Summary Income Statements [Abstract]
Income - Interest income from subordinated debentures issued by Pinnacle Financial													2,218,000	2,082,000	2,749,000
Net income (loss)													2,218,000	2,082,000	2,749,000
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				82,476,000				82,476,000				82,476,000	82,476,000	82,476,000	82,476,000
Net income (loss)													2,218,000	2,082,000	2,749,000
Issuance of trust preferred securities													0	0	0
Dividends [Abstract]
Trust preferred securities													(2,622,000)	(2,017,000)	(2,669,000)
Common- paid to Pinnacle Financial													(67,000)	(65,000)	(80,000)
Ending Balances	82,476,000				82,476,000				82,476,000				82,476,000	82,476,000	82,476,000
Trust [Member] | Trust Preferred Securities [Member]
Combined Summary Balance Sheets [Abstract]
Total stockholders' equity	80,000,000				80,000,000				80,000,000				80,000,000	80,000,000	80,000,000
Combined Summary Income Statements [Abstract]
Net income (loss)													0	0	0
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				80,000,000				80,000,000				80,000,000	80,000,000	80,000,000	80,000,000
Net income (loss)													0	0	0
Issuance of trust preferred securities													0	0	0
Dividends [Abstract]
Trust preferred securities													0	0	0
Common- paid to Pinnacle Financial													0	0	0
Ending Balances	80,000,000				80,000,000				80,000,000				80,000,000	80,000,000	80,000,000
Trust [Member] | Common Stock [Member]
Combined Summary Balance Sheets [Abstract]
Total stockholders' equity	2,476,000				2,476,000				2,476,000				2,476,000	2,476,000	2,476,000
Combined Summary Income Statements [Abstract]
Net income (loss)													0	0	0
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				2,476,000				2,476,000				2,476,000	2,476,000	2,476,000	2,476,000
Net income (loss)													0	0	0
Issuance of trust preferred securities													0	0	0
Dividends [Abstract]
Trust preferred securities													0	0	0
Common- paid to Pinnacle Financial													0	0	0
Ending Balances	2,476,000				2,476,000				2,476,000				2,476,000	2,476,000	2,476,000
Trust [Member] | Retained Earnings [Member]
Combined Summary Balance Sheets [Abstract]
Total stockholders' equity	0				0				0				0	0	0
Combined Summary Income Statements [Abstract]
Net income (loss)													2,218,000	2,082,000	2,749,000
Combined Summary Statements of Stockholder's Equity [Abstract]
Balances				0				0				0	0	0	0
Net income (loss)													2,218,000	2,082,000	2,749,000
Issuance of trust preferred securities													0	0	0
Dividends [Abstract]
Trust preferred securities													(2,151,000)	(2,017,000)	(2,669,000)
Common- paid to Pinnacle Financial													(67,000)	(65,000)	(80,000)
Ending Balances	0				0				0				0	0	0
Trust I [Member]
Investments in and Advances to Affiliates [Line Items]
Date Established													Dec. 29, 2003
Maturity													Dec. 30, 2033
Common Securities	310,000												310,000
Trust Preferred Securities	10,000,000												10,000,000
Floating Interest Rate													Libor + 2.80%
Basis spread on floating interest rate (in hundredths)	2.80%												2.80%
Interest Rate at end of period (in hundredths)	3.11%												3.11%
Combined Summary Balance Sheets [Abstract]
Common securities (100% owned by Pinnacle Financial)	310,000												310,000
Trust II [Member]
Investments in and Advances to Affiliates [Line Items]
Date Established													Sep. 15, 2005
Maturity													Sep. 30, 2035
Common Securities	619,000												619,000
Trust Preferred Securities	20,000,000												20,000,000
Floating Interest Rate													Libor + 1.40%
Basis spread on floating interest rate (in hundredths)	1.40%												1.40%
Interest Rate at end of period (in hundredths)	1.71%												1.71%
Combined Summary Balance Sheets [Abstract]
Common securities (100% owned by Pinnacle Financial)	619,000												619,000
Trust III [Member]
Investments in and Advances to Affiliates [Line Items]
Date Established													Sep. 07, 2006
Maturity													Sep. 30, 2036
Common Securities	619,000												619,000
Trust Preferred Securities	20,000,000												20,000,000
Floating Interest Rate													Libor + 1.65%
Basis spread on floating interest rate (in hundredths)	1.65%												1.65%
Interest Rate at end of period (in hundredths)	1.96%												1.96%
Combined Summary Balance Sheets [Abstract]
Common securities (100% owned by Pinnacle Financial)	619,000												619,000
Trust IV [Member]
Investments in and Advances to Affiliates [Line Items]
Date Established													Oct. 31, 2007
Maturity													Sep. 30, 2037
Common Securities	928,000												928,000
Trust Preferred Securities	30,000,000												30,000,000
Floating Interest Rate													Libor + 2.85%
Basis spread on floating interest rate (in hundredths)	2.85%												2.85%
Interest Rate at end of period (in hundredths)	3.16%												3.16%
Combined Summary Balance Sheets [Abstract]
Common securities (100% owned by Pinnacle Financial)	$ 928,000												$ 928,000