Loans and Allowance for Loan Losses (Details 1) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 2,048,941,000	$ 2,035,258,000
Financing Receivable Acquired Not Covered	300,700,000	347,200,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	108,244,000	114,757,000
Financing Receivable Not Covered by Loss Sharing Agreement	1,100,280,000	1,034,686,000
Total Loans	1,208,524,000	1,149,443,000
Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	23,370,000	33,447,000
Financing Receivable Not Covered by Loss Sharing Agreement	174,178,000	183,747,000
Total Loans	197,548,000	217,194,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	8,983,000	10,898,000
Financing Receivable Not Covered by Loss Sharing Agreement	165,540,000	150,870,000
Total Loans	174,523,000	161,768,000
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	0	0
Financing Receivable Not Covered by Loss Sharing Agreement	14,949,000	13,209,000
Total Loans	14,949,000	13,209,000
Total Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	140,597,000	159,102,000
Financing Receivable Not Covered by Loss Sharing Agreement	1,454,947,000	1,382,512,000
Total Loans	1,595,544,000	1,541,614,000
Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	212,000	215,000
Financing Receivable Not Covered by Loss Sharing Agreement	32,913,000	34,514,000
Total Loans	33,125,000	34,729,000
Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	76,156,000	87,015,000
Financing Receivable Not Covered by Loss Sharing Agreement	333,281,000	359,260,000
Total Loans	409,437,000	446,275,000
Consumer and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	2,317,000	2,598,000
Financing Receivable Not Covered by Loss Sharing Agreement	8,518,000	10,042,000
Total Loans	10,835,000	12,640,000
Total Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Covered by Loss Sharing Agreement	219,282,000	248,930,000
Financing Receivable Not Covered by Loss Sharing Agreement	1,829,659,000	1,786,328,000
Total Loans	$ 2,048,941,000	$ 2,035,258,000