Loans and Allowance for Loan Losses, Impaired Financing Receivable (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Recorded investment	$ 40,821,000		$ 47,855,000		$ 40,821,000		$ 47,855,000
Unpaid principal balance	42,129,000		58,981,000		42,129,000		58,981,000
Related allowance	2,659,000	[1]	4,440,000	[1]	2,659,000	[1]	4,440,000	[1]	4,400,000
Average recorded investment					50,456,000		60,792,000
Interest income recognozed					0		42,000
Increase in interest income if nonaccrual loans were on accrual status	618,000		1,100,000		1,100,000		2,700,000
Collateral Dependent Nonaccrual Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	30,636,000		28,546,000		30,636,000		28,546,000
Unpaid principal balance	31,426,000		34,699,000		31,426,000		34,699,000
Related allowance	0	[1]	0	[1]	0	[1]	0	[1]
Average recorded investment					36,564,000		35,567,000
Interest income recognozed					0		42,000
Collateral Dependent Nonaccrual Loans [Member] | Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	2,239,000		3,036,000		2,239,000		3,036,000
Unpaid principal balance	2,333,000		3,546,000		2,333,000		3,546,000
Related allowance	0	[1]	0	[1]	0	[1]	0	[1]
Average recorded investment					2,806,000		3,689,000
Interest income recognozed					0		0
Collateral Dependent Nonaccrual Loans [Member] | Construction and land development [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	2,942,000		6,917,000		2,942,000		6,917,000
Unpaid principal balance	3,048,000		9,093,000		3,048,000		9,093,000
Related allowance	0	[1]	0	[1]	0	[1]	0	[1]
Average recorded investment					3,320,000		9,288,000
Interest income recognozed					0		37,000
Collateral Dependent Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	11,220,000		9,248,000		11,220,000		9,248,000
Unpaid principal balance	11,386,000		9,961,000		11,386,000		9,961,000
Related allowance	0	[1]	0	[1]	0	[1]	0	[1]
Average recorded investment					13,675,000		10,140,000
Interest income recognozed					0		0
Collateral Dependent Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	14,235,000		9,345,000		14,235,000		9,345,000
Unpaid principal balance	14,659,000		12,099,000		14,659,000		12,099,000
Related allowance	0	[1]	0	[1]	0	[1]	0	[1]
Average recorded investment					16,763,000		12,450,000
Interest income recognozed					0		5,000
Collateral Dependent Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0		0		0
Unpaid principal balance	0		0		0		0
Related allowance	0	[1]	0	[1]	0	[1]	0	[1]
Average recorded investment					0		0
Interest income recognozed					0		0
Cash Flow Dependent Nonaccrual Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	10,185,000		19,309,000		10,185,000		19,309,000
Unpaid principal balance	10,703,000		24,282,000		10,703,000		24,282,000
Related allowance	2,659,000	[1]	4,440,000	[1]	2,659,000	[1]	4,440,000	[1]
Average recorded investment					13,892,000		25,225,000
Interest income recognozed					0		0
Cash Flow Dependent Nonaccrual Loans [Member] | Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	3,204,000		8,854,000		3,204,000		8,854,000
Unpaid principal balance	3,428,000		11,041,000		3,428,000		11,041,000
Related allowance	1,566,000	[1]	2,767,000	[1]	1,566,000	[1]	2,767,000	[1]
Average recorded investment					3,769,000		11,497,000
Interest income recognozed					0		0
Cash Flow Dependent Nonaccrual Loans [Member] | Construction and land development [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	3,097,000		6,048,000		3,097,000		6,048,000
Unpaid principal balance	3,180,000		6,822,000		3,180,000		6,822,000
Related allowance	281,000	[1]	1,264,000	[1]	281,000	[1]	1,264,000	[1]
Average recorded investment					4,360,000		7,074,000
Interest income recognozed					0		0
Cash Flow Dependent Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	2,424,000		3,239,000		2,424,000		3,239,000
Unpaid principal balance	2,559,000		4,902,000		2,559,000		4,902,000
Related allowance	507,000	[1]	301,000	[1]	507,000	[1]	301,000	[1]
Average recorded investment					4,070,000		5,005,000
Interest income recognozed					0		0
Cash Flow Dependent Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	1,001,000		617,000		1,001,000		617,000
Unpaid principal balance	1,052,000		661,000		1,052,000		661,000
Related allowance	209,000	[1]	57,000	[1]	209,000	[1]	57,000	[1]
Average recorded investment					1,101,000		792,000
Interest income recognozed					0		0
Cash Flow Dependent Nonaccrual Loans [Member] | Consumer and Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded investment	459,000		551,000		459,000		551,000
Unpaid principal balance	484,000		856,000		484,000		856,000
Related allowance	96,000	[1]	51,000	[1]	96,000	[1]	51,000	[1]
Average recorded investment					592,000		857,000
Interest income recognozed					$ 0		$ 0

[1] Collateral dependent loans are typically charged-off to their net realizable value pursuant to requirements of our primary regulator and no specific allowance is carried related to those loans.