Loans and Allowance for Loan Losses (Details) (USD $)	9 Months Ended			12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Loans and Allowance for Loan Losses [Abstract]
Percentage of loan portfolio as commercial loan (in hundredths)	75.00%
Risk rated loans	$ 500,000
Financing Receivable, Recorded Investment [Line Items]
Loans	4,421,250,676			4,144,493,486
Potential problem loans not included in nonperforming assets	87,500,000			65,000,000
Average balance of impaired loans	22,060,000			21,484,000
Estimated increase in interest income if nonaccrual loans had been on accrual status	682,000		901,000
Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,478,869,000			1,383,435,000
Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	706,801,000			695,616,000
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	322,090,000			316,191,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,724,086,000			1,605,547,000
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	189,405,000			143,704,000
Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,391,993,000			4,106,664,000
Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,471,383,000			1,360,965,000
Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	696,641,000			686,343,000
Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	316,616,000			315,008,000
Accruing Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,718,723,000			1,601,162,000
Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	188,630,000			143,186,000
Accruing Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,234,886,000			3,979,630,000
Accruing Loans [Member] | Pass [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,441,581,000			1,332,387,000
Accruing Loans [Member] | Pass [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	680,485,000			670,412,000
Accruing Loans [Member] | Pass [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	283,725,000			275,876,000
Accruing Loans [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,640,609,000			1,557,923,000
Accruing Loans [Member] | Pass [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	188,486,000			143,032,000
Accruing Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	69,604,000			62,006,000
Accruing Loans [Member] | Special Mention [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,834,000			8,282,000
Accruing Loans [Member] | Special Mention [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,660,000			1,824,000
Accruing Loans [Member] | Special Mention [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	26,293,000			31,835,000
Accruing Loans [Member] | Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	32,674,000			20,065,000
Accruing Loans [Member] | Special Mention [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	143,000			0
Accruing Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	87,503,000	[1]		65,028,000	[1]
Accruing Loans [Member] | Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,968,000	[1]		20,296,000	[1]
Accruing Loans [Member] | Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	13,496,000	[1]		14,107,000	[1]
Accruing Loans [Member] | Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,598,000	[1]		7,297,000	[1]
Accruing Loans [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	45,440,000	[1]		23,174,000	[1]
Accruing Loans [Member] | Substandard [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,000	[1]		154,000	[1]
Nonaccrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,652,000			18,183,000
Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,486,000			9,017,000
Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,248,000			5,289,000
Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,474,000			1,070,000
Nonaccrual Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,948,000			2,565,000
Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	496,000			242,000
Nonaccrual Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,652,000			18,183,000
Nonaccrual Loans [Member] | Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,486,000			9,017,000
Nonaccrual Loans [Member] | Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,248,000			5,289,000
Nonaccrual Loans [Member] | Substandard [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,474,000			1,070,000
Nonaccrual Loans [Member] | Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,948,000			2,565,000
Nonaccrual Loans [Member] | Substandard [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	496,000			242,000
Nonaccrual Loans [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			0
Nonaccrual Loans [Member] | Doubtful [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			0
Nonaccrual Loans [Member] | Doubtful [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0			0
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			0
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	7,606,000	[2]		19,646,000	[2]
Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		13,453,000	[2]
Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,912,000	[2]		3,984,000	[2]
Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		113,000	[2]
Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,415,000	[2]		1,820,000	[2]
Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	279,000	[2]		276,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	396,000	[2]		4,939,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		2,564,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	64,000	[2]		1,666,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		113,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	253,000	[2]		320,000	[2]
Troubled Debt Restructurings [Member] | Pass [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	79,000	[2]		276,000	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,015,000	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		0	[2]
Troubled Debt Restructurings [Member] | Special Mention [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	815,000	[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	200,000	[2]		0	[2]
Troubled Debt Restructurings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,195,000	[2]		14,707,000	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[2]		10,889,000	[2]
Troubled Debt Restructurings [Member] | Substandard [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,033,000	[2]		2,318,000	[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	3,162,000	[2]		1,500,000	[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	29,258,000			37,829,000
Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,486,000			22,470,000
Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	10,160,000			9,273,000
Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,474,000			1,183,000
Impaired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,363,000			4,385,000
Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 775,000			$ 518,000

[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 nonaccrual loans and troubled debt restructurings. Potential problem loans, which are not included in nonaccrual loans, amounted to approximately $87.5 million at September 30, 2014, compared to $65.0 million at December 31, 2013.

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