Loans and Allowance for Loan Losses (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Loans and Allowance for Loan Losses [Abstract]
Percentage of loan portfolio as commercial loan (in hundredths)	77.00%
Risk rated loans	$ 500,000
Financing Receivable, Recorded Investment [Line Items]
Loans	3,712,162,430		3,291,350,857	[1]
Potential problem loans not included in nonperforming assets	105,400,000		135,400,000
Principal balance of nonaccrual loans	22,823,000		47,855,000
Average balance of impaired loans	38,400,000		60,800,000
Estimated increase in interest income if nonaccrual loans had been on accrual status	1,400,000		5,000,000		7,100,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,446,578,000		1,145,735,000	[1]
Principal balance of nonaccrual loans	3,038,000		11,890,000
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	313,552,000		274,248,000	[1]
Principal balance of nonaccrual loans	4,509,000		12,965,000
Unallocated [Member]
Financing Receivable, Recorded Investment [Line Items]
Principal balance of nonaccrual loans	1,200,000		3,227,000
Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	679,926,000		695,745,000	[1]
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Principal balance of nonaccrual loans	8,091,000		6,735,000
Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,178,196,000		1,110,962,000	[1]
Principal balance of nonaccrual loans	5,906,000		12,487,000
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	93,910,000		64,661,000	[1]
Principal balance of nonaccrual loans	79,000		551,000
Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	50,275,000	[1]	71,271,000	[1]
Impaired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,725,000	[1]	13,735,000	[1]
Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,580,000	[1]	13,042,000	[1]
Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,217,000	[1]	18,361,000	[1]
Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	29,555,000	[1]	25,340,000	[1]
Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	198,000	[1]	793,000	[1]
Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,661,887,000		3,220,080,000
Accruing Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,442,853,000		1,132,000,000
Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	308,972,000		261,206,000
Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	667,709,000		677,384,000
Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,148,641,000		1,085,622,000
Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	93,712,000		63,868,000
Nonaccrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	22,823,000		47,855,000
Nonaccrual Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,038,000		11,890,000
Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,509,000		12,965,000
Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,906,000
Nonaccrual Loans [Member] | Commercial Real Estate Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			12,487,000
Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	9,291,000		9,962,000
Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	79,000		551,000
Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	27,452,000	[1]	23,416,000	[1]
Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	687,000	[1]	1,845,000	[1]
Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	71,000	[1]	77,000	[1]
Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,311,000	[1]	5,874,000	[1]
Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	20,264,000	[1]	15,378,000	[1]
Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	119,000	[1]	242,000	[1]
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	9,020,000	[1]
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	502,000	[1]
Pass [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	71,000	[1]
Pass [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,623,000	[1]
Pass [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,705,000	[1]
Pass [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	119,000	[1]
Pass [Member] | Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,486,996,000		3,004,795,000
Pass [Member] | Accruing Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,390,207,000		1,098,898,000
Pass [Member] | Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	259,878,000		204,696,000
Pass [Member] | Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	649,571,000		643,924,000
Pass [Member] | Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,093,628,000		994,059,000
Pass [Member] | Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	93,712,000		63,218,000
Pass [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			5,092,000	[1]
Pass [Member] | Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			949,000	[1]
Pass [Member] | Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			77,000	[1]
Pass [Member] | Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			3,631,000	[1]
Pass [Member] | Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			193,000	[1]
Pass [Member] | Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			242,000	[1]
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Special Mention [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Special Mention [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Special Mention [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Special Mention [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Special Mention [Member] | Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	69,517,000		79,859,000
Special Mention [Member] | Accruing Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	23,133,000		17,029,000
Special Mention [Member] | Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	29,472,000		27,553,000
Special Mention [Member] | Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,242,000		15,225,000
Special Mention [Member] | Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,670,000		19,403,000
Special Mention [Member] | Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0		649,000
Special Mention [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Special Mention [Member] | Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Special Mention [Member] | Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Special Mention [Member] | Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Special Mention [Member] | Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Special Mention [Member] | Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	18,432,000	[1]
Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	185,000	[1]
Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,688,000	[1]
Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,559,000	[1]
Substandard [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]
Substandard [Member] | Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	105,374,000	[2]	135,426,000	[2]
Substandard [Member] | Accruing Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	29,513,000	[2]	16,073,000	[2]
Substandard [Member] | Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,622,000	[2]	28,957,000	[2]
Substandard [Member] | Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	13,896,000	[2]	18,235,000	[2]
Substandard [Member] | Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	42,343,000	[2]	72,160,000	[2]
Substandard [Member] | Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]	1,000	[2]
Substandard [Member] | Nonaccrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	22,790,000		46,662,000
Substandard [Member] | Nonaccrual Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,035,000		11,194,000
Substandard [Member] | Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,509,000		12,965,000
Substandard [Member] | Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,877,000		11,990,000
Substandard [Member] | Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	9,290,000		9,962,000
Substandard [Member] | Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	79,000		551,000
Substandard [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			18,324,000	[1]
Substandard [Member] | Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			896,000	[1]
Substandard [Member] | Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Substandard [Member] | Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			2,243,000	[1]
Substandard [Member] | Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			15,185,000	[1]
Substandard [Member] | Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans			0	[1]
Doubtful [Member] | Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	33,000		1,193,000
Doubtful [Member] | Impaired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,000		696,000
Doubtful [Member] | Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0		0
Doubtful [Member] | Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	29,000		497,000
Doubtful [Member] | Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,000		0
Doubtful [Member] | Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 0		$ 0

[1] Troubled debt restructurings are presented as an impaired loan; however, they continue to accrue interest at contractual rates.

[2] Potential problem loans represent those loans with a well-defined weakness and where information about possible credit problems of borrowers has caused management to have doubts about the borrower's ability to comply with present repayment terms. This definition is believed to be substantially consistent with the standards established by Pinnacle Bank's primary regulators for loans classified as substandard, excluding the impact of substandard nonperforming loans and substandard troubled debt restructurings. Potential problem loans, which are not included in nonperforming assets, amounted to approximately $105.4 million at December 31, 2012, compared to $135.4 million at December 31, 2011.