Bank Loans (Changes in the Allowance for Loan Losses) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Bank Loans
Allowance for Loan and Lease Loss, Residential Real Estate	$ (5,000.0)	$ (216,000)	$ (213,000.0)
Provision for loan losses	2,925,000.0	460,000	604,000.0
Allowance for Loan and Lease Losses, Write-offs, Constuction and Land			(859,000.0)
Allowance for Loan and Lease Losses, Write-offs, Real Estate Construction Loans	(5,000.0)		(294,000.0)
Allowance for Loan and Lease Losses, Write-offs, Other		(2,000)	(25,000.0)
Total charge-offs	(10,000.0)	(218,000)	(1,391,000.0)
Recoveries	$ 54,000.0	$ 387,000	$ 41,000.0