Allowance for Loan Losses, Nonperforming Assets and Impaired Loans, Non-impaired loans by credit quality indicator (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended																																																													9 Months Ended																																																												9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012 Pass [Member]	Dec. 31, 2011 Pass [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial and Industrial [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Pass [Member] Real Estate Construction [Member] Construction, 1-4 Family Residential [Member]	Sep. 30, 2012 Pass [Member] Real Estate Construction [Member] Construction other [Member]	Sep. 30, 2012 Pass [Member] Consumer Real Estate [Member] Equity lines [Member]	Dec. 31, 2011 Pass [Member] Consumer Real Estate [Member] Equity lines [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Consumer Real Estate [Member] Closed end Consumer Real Estate [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Consumer Real Estate [Member] Consumer Construction [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Pass [Member] Consumer Real Estate [Member] Residential closed end first liens [Member]	Sep. 30, 2012 Pass [Member] Consumer Real Estate [Member] Residential closed end junior liens [Member]	Sep. 30, 2012 Pass [Member] Commercial Real Estate [Member] Commercial real estate, other [Member]	Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Commercial real estate, other [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Pass [Member] Commercial Real Estate [Member] Commercial real estate, owner occupied [Member]	Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] College Housing [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Office/Retail [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Nursing Homes [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Hotel [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Municipalities [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Pass [Member] Commercial Real Estate [Member] Multifamily real estate [Member]	Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Medical Professionals [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Religious Organizations [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Convenience Stores [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Entertainment and Sports [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Nonprofits [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] Restaurants [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Commercial Real Estate [Member] General Contractors [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Pass [Member] Commercial Non Real Estate [Member] Commercial and Industrial [Member]	Sep. 30, 2012 Pass [Member] Public Sector and IDA [Member] States & Political Subdivisions [Member]	Sep. 30, 2012 Pass [Member] Consumer Non Real Estate [Member] Automobile [Member]	Sep. 30, 2012 Pass [Member] Consumer Non Real Estate [Member] Other Consumer [Member]	Sep. 30, 2012 Pass [Member] Consumer Non Real Estate [Member] Credit cards [Member]	Dec. 31, 2011 Pass [Member] Consumer Non Real Estate [Member] Credit cards [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Consumer Non Real Estate [Member] Consumer General [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Consumer Non Real Estate [Member] Consumer Overdraft [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Construction Development and Other land [Member] Residential [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Pass [Member] Construction Development and Other land [Member] Commercial [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Special Mention [Member]	Dec. 31, 2011 Special Mention [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial and Industrial [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Special Mention [Member] Real Estate Construction [Member] Construction, 1-4 Family Residential [Member]	Sep. 30, 2012 Special Mention [Member] Real Estate Construction [Member] Construction other [Member]	Sep. 30, 2012 Special Mention [Member] Consumer Real Estate [Member] Equity lines [Member]	Dec. 31, 2011 Special Mention [Member] Consumer Real Estate [Member] Equity lines [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Consumer Real Estate [Member] Closed end Consumer Real Estate [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Consumer Real Estate [Member] Consumer Construction [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Special Mention [Member] Consumer Real Estate [Member] Residential closed end first liens [Member]	Sep. 30, 2012 Special Mention [Member] Consumer Real Estate [Member] Residential closed end junior liens [Member]	Sep. 30, 2012 Special Mention [Member] Commercial Real Estate [Member] Commercial real estate, other [Member]	Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Commercial real estate, other [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Special Mention [Member] Commercial Real Estate [Member] Commercial real estate, owner occupied [Member]	Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] College Housing [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Office/Retail [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Nursing Homes [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Hotel [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Municipalities [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Special Mention [Member] Commercial Real Estate [Member] Multifamily real estate [Member]	Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Medical Professionals [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Religious Organizations [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Convenience Stores [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Entertainment and Sports [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Nonprofits [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] Restaurants [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Commercial Real Estate [Member] General Contractors [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Special Mention [Member] Commercial Non Real Estate [Member] Commercial and Industrial [Member]	Sep. 30, 2012 Special Mention [Member] Public Sector and IDA [Member] States & Political Subdivisions [Member]	Sep. 30, 2012 Special Mention [Member] Consumer Non Real Estate [Member] Automobile [Member]	Sep. 30, 2012 Special Mention [Member] Consumer Non Real Estate [Member] Other Consumer [Member]	Sep. 30, 2012 Special Mention [Member] Consumer Non Real Estate [Member] Credit cards [Member]	Dec. 31, 2011 Special Mention [Member] Consumer Non Real Estate [Member] Credit cards [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Consumer Non Real Estate [Member] Consumer General [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Consumer Non Real Estate [Member] Consumer Overdraft [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Construction Development and Other land [Member] Residential [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Special Mention [Member] Construction Development and Other land [Member] Commercial [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Classified (Excluding Impaired) [Member]	Dec. 31, 2011 Classified (Excluding Impaired) [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial and Industrial [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Classified (Excluding Impaired) [Member] Real Estate Construction [Member] Construction, 1-4 Family Residential [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Real Estate Construction [Member] Construction other [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Consumer Real Estate [Member] Equity lines [Member]	Dec. 31, 2011 Classified (Excluding Impaired) [Member] Consumer Real Estate [Member] Equity lines [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Consumer Real Estate [Member] Closed end Consumer Real Estate [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Consumer Real Estate [Member] Consumer Construction [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Classified (Excluding Impaired) [Member] Consumer Real Estate [Member] Residential closed end first liens [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Consumer Real Estate [Member] Residential closed end junior liens [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Commercial real estate, other [Member]	Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Commercial real estate, other [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Commercial real estate, owner occupied [Member]	Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] College Housing [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Office/Retail [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Nursing Homes [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Hotel [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Municipalities [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Multifamily real estate [Member]	Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Medical Professionals [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Religious Organizations [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Convenience Stores [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Entertainment and Sports [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Nonprofits [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] Restaurants [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Commercial Real Estate [Member] General Contractors [Member] Scenario, Previously Reported [Member]		Sep. 30, 2012 Classified (Excluding Impaired) [Member] Commercial Non Real Estate [Member] Commercial and Industrial [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Public Sector and IDA [Member] States & Political Subdivisions [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Consumer Non Real Estate [Member] Automobile [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Consumer Non Real Estate [Member] Other Consumer [Member]	Sep. 30, 2012 Classified (Excluding Impaired) [Member] Consumer Non Real Estate [Member] Credit cards [Member]	Dec. 31, 2011 Classified (Excluding Impaired) [Member] Consumer Non Real Estate [Member] Credit cards [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Consumer Non Real Estate [Member] Consumer General [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Consumer Non Real Estate [Member] Consumer Overdraft [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Construction Development and Other land [Member] Residential [Member] Scenario, Previously Reported [Member]		Dec. 31, 2011 Classified (Excluding Impaired) [Member] Construction Development and Other land [Member] Commercial [Member] Scenario, Previously Reported [Member]
Financing Receivable, Recorded Investment [Line Items]
Threshold period for considering loans as special mention or classified (in days)	75 days
Increase in percentage of allocation for internal and external factors used for estimating credit risk for non-impaired loans (in hundredths)																																																														50.00%																																																												100.00%
Non-impaired loans		$ 563,498	$ 563,687	[1]	$ 37,252	[1]	$ 15,284	$ 27,842	$ 18,265	$ 17,971	[1]	$ 87,882	[1]	$ 2,050	[1]	$ 112,188	$ 6,778	$ 91,482	$ 63,422	[1]	$ 165,685	$ 88,157	[1]	$ 73,106	[1]	$ 16,173	[1]	$ 24,498	[1]	$ 19,230	[1]	$ 32,342	$ 18,577	[1]	$ 15,852	[1]	$ 10,519	[1]	$ 7,346	[1]	$ 3,265	[1]	$ 6,138	[1]	$ 4,550	[1]	$ 34,721	$ 26,589	$ 12,913	$ 12,908	$ 6,501	$ 6,594	[1]	$ 22,679	[1]	$ 285	[1]	$ 15,732	[1]	$ 22,409	[1]	$ 11,696	$ 7,945	[1]	$ 196	[1]	$ 0	$ 2,961	$ 98	$ 0	[1]	$ 595	[1]	$ 0	[1]	$ 702	$ 124	$ 3,132	$ 0	[1]	$ 986	$ 452	[1]	$ 420	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 3,533	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 3,170	[1]	$ 0	[1]	$ 109	[1]	$ 13	$ 0	$ 81	$ 66	$ 0	$ 0	[1]	$ 42	[1]	$ 0	[1]	$ 0	[1]	$ 2,961	[1]	$ 4,302	$ 4,242	[1]	$ 137	[1]	$ 0	$ 89	$ 72	$ 14	[1]	$ 1,332	[1]	$ 0	[1]	$ 2,096	$ 140	$ 0	$ 790	[1]	$ 1,087	$ 215	[1]	$ 267	[1]	$ 0	[1]	$ 616	[1]	$ 0	[1]	$ 262	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 387	[1]	$ 247	[1]	$ 461	$ 0	$ 51	$ 44	$ 0	$ 1	[1]	$ 105	[1]	$ 1	[1]	$ 0	[1]	$ 130	[1]

[1] Segments at December 31, 2011 are reported using the segmentation method in effect for 2011. The Company began reporting under revised segments beginning in 2012.