Loans and Allowance for Loan Losses (Details) (USD $)	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Loans and Allowance for Loan Losses [Abstract]
Percentage of loan portfolio as commercial loan (in hundredths)	76.00%
Risk rated loans	$ 500,000
Financing Receivable, Recorded Investment [Line Items]
Loans	3,969,302,182			3,712,162,430
Potential problem loans not included in nonperforming assets	71,100,000			105,400,000
Average balance of impaired loans	21,035,000			38,413,000
Estimated increase in interest income if nonaccrual loans had been on accrual status	901,000		1.5
Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,326,839,000			1,178,196,000
Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	687,258,000			679,926,000
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	319,974,000			313,552,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,513,631,000			1,446,578,000
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	121,600,000			93,910,000
Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,929,651,000			3,661,887,000
Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,302,846,000			1,148,641,000
Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	678,065,000			667,709,000
Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	318,551,000			308,972,000
Accruing Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,509,125,000			1,442,853,000
Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	121,064,000			93,712,000
Accruing Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,792,044,000			3,486,996,000
Accruing Loans [Member] | Pass [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,270,788,000			1,093,628,000
Accruing Loans [Member] | Pass [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	664,152,000			649,571,000
Accruing Loans [Member] | Pass [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	275,561,000			259,878,000
Accruing Loans [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,460,479,000			1,390,207,000
Accruing Loans [Member] | Pass [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	121,064,000			93,712,000
Accruing Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	66,529,000			69,517,000
Accruing Loans [Member] | Special Mention [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,298,000			12,670,000
Accruing Loans [Member] | Special Mention [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,095,000			4,242,000
Accruing Loans [Member] | Special Mention [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	33,292,000			29,472,000
Accruing Loans [Member] | Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,844,000			23,133,000
Accruing Loans [Member] | Special Mention [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			0
Accruing Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	71,078,000	[1]		105,374,000	[1]
Accruing Loans [Member] | Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,760,000	[1]		42,343,000	[1]
Accruing Loans [Member] | Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,818,000	[1]		13,896,000	[1]
Accruing Loans [Member] | Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	9,698,000	[1]		19,622,000	[1]
Accruing Loans [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	26,802,000	[1]		29,513,000	[1]
Accruing Loans [Member] | Substandard [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]		0	[1]
Nonaccrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,990,000			22,823,000
Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,517,000			9,291,000
Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,195,000			5,906,000
Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,307,000			4,509,000
Nonaccrual Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,728,000			3,038,000
Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	243,000			79,000
Nonaccrual Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,990,000			22,790,000
Nonaccrual Loans [Member] | Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,517,000			9,290,000
Nonaccrual Loans [Member] | Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,195,000			5,877,000
Nonaccrual Loans [Member] | Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,307,000			4,509,000
Nonaccrual Loans [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,728,000			3,035,000
Nonaccrual Loans [Member] | Substandard [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	243,000			79,000
Nonaccrual Loans [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			33,000
Nonaccrual Loans [Member] | Doubtful [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			1,000
Nonaccrual Loans [Member] | Doubtful [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			29,000
Nonaccrual Loans [Member] | Doubtful [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			0
Nonaccrual Loans [Member] | Doubtful [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			3,000
Nonaccrual Loans [Member] | Doubtful [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			0
Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,661,000	[2]		27,452,000	[2]
Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	13,476,000	[2]		20,264,000	[2]
Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,998,000	[2]		6,311,000	[2]
Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	116,000	[2]		71,000	[2]
Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,778,000	[2]		687,000	[2]
Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	293,000	[2]		119,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,581,000	[2]		9,020,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	145,000	[2]		4,705,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,749,000	[2]		3,623,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	116,000	[2]		71,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	278,000	[2]		502,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	293,000	[2]		119,000	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,441,000	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,441,000	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Troubled Debt Restructurings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	13,639,000	[2]		18,432,000	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,890,000	[2]		15,559,000	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,249,000	[2]		2,688,000	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,500,000	[2]		185,000	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	39,651,000			50,275,000
Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	23,993,000			29,555,000
Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	9,193,000			12,217,000
Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,423,000			4,580,000
Impaired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,506,000			3,725,000
Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 536,000			$ 198,000

[1] 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 nonaccrual loans and substandard troubled debt restructurings. Potential problem loans, which are not included in nonaccrual loans, amounted to approximately $71.1 million at September 30, 2013, compared to $105.4 million at December 31, 2012.

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