Loans and Allowance for Loan Losses (Details) (USD $)	6 Months Ended
	Jun. 30, 2012		Dec. 31, 2011
Loans and Allowance for Loan Losses [Abstract]
Percentage of loan portfolio as commercial loan (in hundredths)	75.00%
Risk rated loans	$ 500,000
Percentage of risk rated annual portfolio, minimum (in hundredths)	70.00%
Financing Receivable, Recorded Investment [Line Items]
Loans	3,444,683,416		3,291,350,857
Potential problem loans not included in nonperforming assets	120,000,000		135,400,000
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,227,275,000		1,145,735,000
Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	289,061,000		274,248,000
Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	687,002,000		695,745,000
Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,167,068,000		1,110,962,000
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	74,277,000		64,661,000
Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	67,447,000		71,271,000
Impaired Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,426,000		13,735,000
Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,473,000		13,042,000
Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,689,000		18,361,000
Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	34,276,000		25,340,000
Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	583,000		793,000
Nonaccrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	40,821,000		47,855,000
Nonaccrual Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,443,000		11,890,000
Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,039,000		12,965,000
Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	13,644,000		12,487,000
Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,236,000		9,962,000
Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	459,000		551,000
Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	26,626,000	[1]	23,416,000	[1]
Troubled Debt Restructurings [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	983,000	[1]	1,845,000	[1]
Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	434,000	[1]	77,000	[1]
Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,045,000	[1]	5,874,000	[1]
Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,040,000	[1]	15,378,000	[1]
Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	124,000	[1]	242,000	[1]
Pass [Member] | Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,092,000	[1]	5,092,000	[1]
Pass [Member] | Impaired Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	728,000	[1]	949,000	[1]
Pass [Member] | Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	74,000	[1]	77,000	[1]
Pass [Member] | Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,833,000	[1]	3,631,000	[1]
Pass [Member] | Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	333,000	[1]	193,000	[1]
Pass [Member] | Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	124,000	[1]	242,000	[1]
Pass [Member] | Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	3,183,275,000		3,004,795,000
Pass [Member] | Accruing Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,182,567,000		1,098,898,000
Pass [Member] | Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	228,825,000		204,696,000
Pass [Member] | Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	645,766,000		643,924,000
Pass [Member] | Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,052,422,000		994,059,000
Pass [Member] | Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	73,695,000		63,218,000
Special Mention [Member] | Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,508,000	[1]	0	[1]
Special Mention [Member] | Impaired Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]	0	[1]
Special Mention [Member] | Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]	0	[1]
Special Mention [Member] | Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]	0	[1]
Special Mention [Member] | Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,508,000	[1]	0	[1]
Special Mention [Member] | Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]	0	[1]
Special Mention [Member] | Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	74,008,000		79,859,000
Special Mention [Member] | Accruing Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19,524,000		17,029,000
Special Mention [Member] | Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	27,067,000		27,553,000
Special Mention [Member] | Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,189,000		15,225,000
Special Mention [Member] | Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	21,228,000		19,403,000
Special Mention [Member] | Accruing Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0		649,000
Substandard [Member] | Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	17,026,000	[1]	18,324,000	[1]
Substandard [Member] | Impaired Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	255,000	[1]	896,000	[1]
Substandard [Member] | Impaired Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	360,000	[1]	0	[1]
Substandard [Member] | Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,212,000	[1]	2,243,000	[1]
Substandard [Member] | Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	14,199,000	[1]	15,185,000	[1]
Substandard [Member] | Impaired Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	[1]	0	[1]
Substandard [Member] | Accruing Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	119,953,000	[2]	135,426,000	[2]
Substandard [Member] | Accruing Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	18,757,000	[2]	16,073,000	[2]
Substandard [Member] | Accruing Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	26,696,000	[2]	28,957,000	[2]
Substandard [Member] | Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,358,000	[2]	18,235,000	[2]
Substandard [Member] | Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	59,142,000	[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	40,423,000		46,662,000
Substandard [Member] | Nonaccrual Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	5,345,000		11,194,000
Substandard [Member] | Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	6,039,000		12,965,000
Substandard [Member] | Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	13,344,000		11,990,000
Substandard [Member] | Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,236,000		9,962,000
Substandard [Member] | Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	459,000		551,000
Doubtful [Member] | Nonaccrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	398,000		1,193,000
Doubtful [Member] | Nonaccrual Loans [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	98,000		696,000
Doubtful [Member] | Nonaccrual Loans [Member] | Construction and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0		0
Doubtful [Member] | Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	300,000		497,000
Doubtful [Member] | Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0		0
Doubtful [Member] | Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 0		$ 0

[1] Troubled debt restructurings are accruing. Troubled debt restructurings are presented as an impaired, however, 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 the OCC, Pinnacle National's primary regulator, 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 $120.0 million at June 30, 2012, compared to $135.4 million at December 31, 2011.