Loans and Allowance for Loan Losses, Financing Receivables Past Due (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 Loans		Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	$ 10,344,000		$ 12,950,000
90 days or more past due and accruing	7,943,000		3,346,000
Total past due and accruing	18,287,000		16,296,000
Nonaccrual	15,606,000	[1]	18,183,000	[1]
Current and accruing	4,147,794,000		4,110,014,000
Total Loans	4,181,687,000		4,144,493,000
Currently performing impaired loans	10,900,000		10,900,000
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	125,000		2,534,000
90 days or more past due and accruing	0		0
Total past due and accruing	125,000		2,534,000
Nonaccrual	6,906,000	[1]	7,750,000	[1]
Current and accruing	694,296,000		669,014,000
Total Loans	701,327,000		679,298,000
Commercial Real Estate All Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	844,000		27,000
90 days or more past due and accruing	7,736,000	[2]	2,232,000
Total past due and accruing	8,580,000		2,259,000
Nonaccrual	239,000	[1]	1,267,000	[1]
Current and accruing	746,026,000		700,611,000
Total Loans	754,845,000		704,137,000
Number of loans brought current with a principal curtailment	1
Principal curtailment	7,600,000
Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	5,239,000		2,215,000
90 days or more past due and accruing	0		0
Total past due and accruing	5,239,000		2,215,000
Nonaccrual	5,679,000	[1]	5,289,000	[1]
Current and accruing	692,674,000		688,112,000
Total Loans	703,592,000		695,616,000
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	849,000		4,839,000
90 days or more past due and accruing	147,000		0
Total past due and accruing	996,000		4,839,000
Nonaccrual	990,000	[1]	1,070,000	[1]
Current and accruing	292,069,000		310,282,000
Total Loans	294,055,000		316,191,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	1,191,000		1,847,000
90 days or more past due and accruing	52,000		825,000
Total past due and accruing	1,243,000		2,672,000
Nonaccrual	1,538,000	[1]	2,565,000	[1]
Current and accruing	1,566,156,000		1,600,310,000
Total Loans	1,568,937,000		1,605,547,000
Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 To 89 days past due and accruing	2,096,000		1,488,000
90 days or more past due and accruing	8,000		289,000
Total past due and accruing	2,104,000		1,777,000
Nonaccrual	254,000	[1]	242,000	[1]
Current and accruing	156,573,000		141,685,000
Total Loans	$ 158,931,000		$ 143,704,000

[1] Approximately $10.9 million of nonaccrual loans as of March 31, 2014 and December 31, 2013, respectively, are currently performing pursuant to their contractual terms.

[2] Represents one commercial real estate loan which, subsequent to March 31, 2014, was brought current with a principal curtailments of $7.6 million.