Loans, Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Without an allowance recorded [Abstract]
Recorded investment	$ 9,000
With an allowance recorded [Abstract]
Recorded investment	20,200	14,500
Related allowance	10,900	5,900
Total allowance recorded [Abstract]
Total impaired loans	29,200	17,600
Commercial [Member]
Without an allowance recorded [Abstract]
Recorded investment	4,219	900
Unpaid principal balance	6,257	2,042
Related allowance	0	6,831
Average recorded investment	2,017	626
Interest income recognized	0	0
With an allowance recorded [Abstract]
Recorded investment	3,435	5,550
Unpaid principal balance	3,631	5,550
Related allowance	1,885	2,724
Average recorded investment	5,397	3,075
Interest income recognized	0	0
Total allowance recorded [Abstract]
Total impaired loans	7,654	6,450
Unpaid principal balance	9,888	7,592
Related allowance	1,885	9,555
Average recorded investment	7,414	3,701
Interest income recognized	0	0
Commercial mortgage [Member]
Without an allowance recorded [Abstract]
Recorded investment	3,582	0
Unpaid principal balance	4,403	0
Related allowance	0	0
Average recorded investment	2,058	310
Interest income recognized	0	0
With an allowance recorded [Abstract]
Recorded investment	7,742	3,672
Unpaid principal balance	8,287	3,672
Related allowance	4,028	712
Average recorded investment	4,090	2,793
Interest income recognized	0	0
Total allowance recorded [Abstract]
Total impaired loans	11,324	3,672
Unpaid principal balance	12,690	3,672
Related allowance	4,028	712
Average recorded investment	6,148	3,103
Interest income recognized	0	0
Construction [Member]
Without an allowance recorded [Abstract]
Recorded investment	276	0
Unpaid principal balance	276	0
Related allowance	0	0
Average recorded investment	911	100
Interest income recognized	0	0
With an allowance recorded [Abstract]
Recorded investment	8,886	4,949
Unpaid principal balance	8,886	4,949
Related allowance	4,899	2,296
Average recorded investment	7,523	2,123
Interest income recognized	0	0
Total allowance recorded [Abstract]
Total impaired loans	9,162	4,949
Unpaid principal balance	9,162	4,949
Related allowance	4,899	2,296
Average recorded investment	8,434	2,223
Interest income recognized	0	0
Residential mortgage [Member]
Without an allowance recorded [Abstract]
Recorded investment	0	1,264
Unpaid principal balance	0	1,414
Related allowance	0	149
Average recorded investment	316	662
Interest income recognized	0	0
With an allowance recorded [Abstract]
Recorded investment	93	0
Unpaid principal balance	93	0
Related allowance	71	0
Average recorded investment	47	5,048
Interest income recognized	0	0
Total allowance recorded [Abstract]
Total impaired loans	93	1,264
Unpaid principal balance	93	1,414
Related allowance	71	149
Average recorded investment	363	5,710
Interest income recognized	0	0
Consumer - home equity [Member]
Without an allowance recorded [Abstract]
Recorded investment	927	927
Unpaid principal balance	927	927
Related allowance	0	3,765
Average recorded investment	927	371
Interest income recognized	0	0
With an allowance recorded [Abstract]
Recorded investment	0	325
Unpaid principal balance	0	325
Related allowance	0	204
Average recorded investment	81	510
Interest income recognized	0	0
Total allowance recorded [Abstract]
Total impaired loans	927	1,252
Unpaid principal balance	927	1,252
Related allowance	0	3,969
Average recorded investment	1,008	881
Interest income recognized	$ 0	$ 0