Securities, AVAILABLE FOR SALE (Details) (USD $)	3 Months Ended					6 Months Ended
	Jun. 30, 2012		Mar. 31, 2012		Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Available-for-sale securities, continuous unrealized loss position [Abstract]
Investments with an Unrealized Loss of less than 12 months, Fair Value	$ 9,629,000					$ 9,629,000		$ 49,017,000
Investments with an Unrealized Loss of less than 12 months, Unrealized Losses	136,000					136,000		367,000
Investments with an Unrealized Loss of 12 months or longer, Fair Value	9,939,000					9,939,000		19,031,000
Investments with an Unrealized Loss of 12 months or longer, Unrealized Losses	38,000					38,000		35,000
Total Investments with an Unrealized Loss, Fair Value	19,568,000					19,568,000		68,048,000
Total Investments with an Unrealized Loss, Unrealized Losses	174,000					174,000		402,000
Available-for-sale Securities, Total	789,738,398					789,738,398		894,962,246
Available-for-sale securities, gross realized gain (loss) [Abstract]
Fair Value of securities sold	18,273,000	[1]	14,360,000	[2]		32,632,321	51,116,046
Gain recognized	99,000		148,000
Loss recognized	0		0
Net	99,000		148,000
Other-than-temporary impairment	0	[3]	34,000	[3]
Gain on the sale of securities, net	98,917		114,000		610,302	212,517	451,199
Weighted average coupon of securities (in hundredths)						0.50%
Number of mortgage backed securities as other-than-temporarily impaired						4
Number of securities sold from the state of California	2					2
U.S. Government Agency Securities [Member]
Available-for-sale securities, continuous unrealized loss position [Abstract]
Investments with an Unrealized Loss of less than 12 months, Fair Value	749,000					749,000		5,452,000
Investments with an Unrealized Loss of less than 12 months, Unrealized Losses	1,000					1,000		9,000
Investments with an Unrealized Loss of 12 months or longer, Fair Value	0					0		0
Investments with an Unrealized Loss of 12 months or longer, Unrealized Losses	0					0		0
Total Investments with an Unrealized Loss, Fair Value	749,000					749,000		5,452,000
Total Investments with an Unrealized Loss, Unrealized Losses	1,000					1,000		9,000
Mortgage-backed Securities [Member]
Available-for-sale securities, continuous unrealized loss position [Abstract]
Investments with an Unrealized Loss of less than 12 months, Fair Value	7,218,000					7,218,000		41,598,000
Investments with an Unrealized Loss of less than 12 months, Unrealized Losses	117,000					117,000		341,000
Investments with an Unrealized Loss of 12 months or longer, Fair Value	9,608,000					9,608,000		17,826,000
Investments with an Unrealized Loss of 12 months or longer, Unrealized Losses	37,000					37,000		30,000
Total Investments with an Unrealized Loss, Fair Value	16,826,000					16,826,000		59,424,000
Total Investments with an Unrealized Loss, Unrealized Losses	154,000					154,000		371,000
State and Municipal Securities [Member]
Available-for-sale securities, continuous unrealized loss position [Abstract]
Investments with an Unrealized Loss of less than 12 months, Fair Value	1,462,000					1,462,000		1,967,000
Investments with an Unrealized Loss of less than 12 months, Unrealized Losses	17,000					17,000		17,000
Investments with an Unrealized Loss of 12 months or longer, Fair Value	331,000					331,000		1,205,000
Investments with an Unrealized Loss of 12 months or longer, Unrealized Losses	1,000					1,000		5,000
Total Investments with an Unrealized Loss, Fair Value	1,793,000					1,793,000		3,172,000
Total Investments with an Unrealized Loss, Unrealized Losses	18,000					18,000		22,000
Corporate Notes [Member]
Available-for-sale securities, continuous unrealized loss position [Abstract]
Investments with an Unrealized Loss of less than 12 months, Fair Value	200,000					200,000		0
Investments with an Unrealized Loss of less than 12 months, Unrealized Losses	1,000					1,000		0
Investments with an Unrealized Loss of 12 months or longer, Fair Value	0					0		0
Investments with an Unrealized Loss of 12 months or longer, Unrealized Losses	0					0		0
Total Investments with an Unrealized Loss, Fair Value	200,000					200,000		0
Total Investments with an Unrealized Loss, Unrealized Losses	1,000					1,000		0
Total Available for Sale Securities [Member]
Available-for-sale securities, continuous unrealized loss position [Abstract]
Available-for-sale Securities, Total	$ 19,600,000					$ 19,600,000

[1] Pinnacle sold the four securities previously identified as OTTI in the second quarter. Additionally, two securities issued by municipalities in the state of California which management believed could be adversely affected by state budgetary issues were also sold during the second quarter.

[2] Pinnacle Financial sold these securities due to their relatively short terms until maturity and a weighted average coupon of 0.50%.

[3] During the first six months of 2012, Pinnacle Financial determined four mortgage-backed securities were other-than-temporarily impaired (OTTI) because of management's intent to sell them in the second quarter of 2012. The decision to sell was based on their relative underperformance compared to expectations.