Loans and Allowance for Loan Losses, Troubled Debt Restructurings (Details) (USD $)	3 Months Ended	6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2013 Contract Loan	Jun. 30, 2013 Loan	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2013 Commercial and Industrial [Member] Contract	Jun. 30, 2012 Commercial and Industrial [Member] Contract	Jun. 30, 2013 Commercial and Industrial [Member] Contract	Jun. 30, 2012 Commercial and Industrial [Member] Contract	Jun. 30, 2013 Commercial Real Estate [Member] Contract	Jun. 30, 2012 Commercial Real Estate [Member] Contract	Jun. 30, 2013 Commercial Real Estate [Member] Contract	Jun. 30, 2012 Commercial Real Estate [Member] Contract	Jun. 30, 2013 Construction and Land [Member] Contract	Jun. 30, 2012 Construction and Land [Member] Contract	Jun. 30, 2013 Construction and Land [Member] Contract	Jun. 30, 2012 Construction and Land [Member] Contract	Jun. 30, 2013 Consumer [Member] Contract	Jun. 30, 2012 Consumer [Member] Contract	Jun. 30, 2013 Consumer [Member] Contract	Jun. 30, 2012 Consumer [Member] Contract	Jun. 30, 2013 Residential Real Estate [Member] Contract	Jun. 30, 2012 Residential Real Estate [Member] Contract	Jun. 30, 2013 Residential Real Estate [Member] Contract	Jun. 30, 2012 Residential Real Estate [Member] Contract	Jun. 30, 2013 Home Equity Line of Credit [Member] Contract	Jun. 30, 2012 Home Equity Line of Credit [Member] Contract	Jun. 30, 2013 Home Equity Line of Credit [Member] Contract	Jun. 30, 2012 Home Equity Line of Credit [Member] Contract	Jun. 30, 2013 Student US Government Guaranteed [Member] Contract	Jun. 30, 2012 Student US Government Guaranteed [Member] Contract	Jun. 30, 2013 Student US Government Guaranteed [Member] Contract	Jun. 30, 2012 Student US Government Guaranteed [Member] Contract
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of contracts	2				0	1	0	1	0	1	2	1	1	3	1	3	0	0	0	0	1	0	1	0	0	0	0	0	0	0	0	0
Troubled debt restructurings, pre-modification outstanding recorded investment	$ 1,108,000				$ 0	$ 237,000	$ 0	$ 237,000	$ 0	$ 1,900,000	$ 2,010,000	$ 1,900,000	$ 808,000	$ 1,800,000	$ 808,000	$ 1,800,000	$ 0	$ 0	$ 0	$ 0	$ 300,000	$ 0	$ 300,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Troubled debt restructurings, post-modification outstanding recorded investment					0	237,000	0	237,000	0	1,900,000	2,010,000	1,900,000	808,000	1,800,000	808,000	1,800,000	0	0	0	0	300,000	0	300,000	0	0	0	0	0	0	0	0	0
Troubled debt restructurings that subsequently defaulted, number of contracts					0	0	1	0	0	0	0	0	0	0	0	0	0		0	0	0		0	0	0		0	0	0		0	0
Troubled debt restructurings that subsequently defaulted, pre-modification outstanding recorded investment		0			0	0	237,000	0	0	0	0	0	0	0	0	0			0	0	0		0	0			0	0			0	0
Troubled debt restructurings that subsequently defaulted, post-modification outstanding recorded investment		0			0	0	237,000	0	0	0	0	0	0	0	0	0			0	0	0		0	0			0	0			0	0
Number of TDR loans secured by business assets	12	12
TDR loans value	9,470,000	9,470,000
Number of TDR loans current and performing	9	9
TDR loans current and performing	8,484,000	8,484,000
Number of TDR loans not performing in accordance with the modified terms	3	3
TDR loans not performing in accordance with modified terms	986,000	986,000
Non-performing Assets, Restructured Loans Still Accruing and Loans Contractually Past Due [Abstract]
Non-accrual loans	6,698,000	6,698,000	10,650,000	7,382,000
Other real estate owned	1,406,000	1,406,000	1,406,000	1,776,000
Non-performing corporate bond investments, at fair value	0	0	0	292,000
Total non-performing assets	8,104,000	8,104,000	12,056,000	9,450,000
Restructured loans still accruing	8,484,000	8,484,000	5,556,000	4,148,000
Student Loans 90 PD Still Accruing	3,220,000	3,220,000	0	0
Loans past due 90 or more days and still accruing	355,000	355,000	132,000	201,000
Total non-performing and other risk assets	$ 20,163,000	$ 20,163,000	$ 17,744,000	$ 13,799,000
Allowance for loan losses to total loans (in hundredths)	1.54%	1.54%	1.39%	2.06%
Non-accrual loans to total loans (in hundredths)	1.51%	1.51%	2.36%	1.61%
Allowance for loan losses to non-accrual loans (in hundredths)	102.06%	102.06%	58.76%	128.00%
Total non-accrual loans and restructured loans still accruing to total loans (in hundredths)	3.43%	3.43%	3.59%	2.51%
Allowance for loan losses to non-accrual loans and restructured loans still accruing (in hundredths)	45.03%	45.03%	38.62%	81.95%
Total non-performing assets to total assets (in hundredths)	1.37%	1.37%	2.00%	1.62%