Significant Accounting Policies (Investments) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Investment [Line Items]
Company owned life insurance	$ 2,000,000
Payments to acquire life insurance policies	5,000,000
Cash surrender value of life insurance	5,981,000		5,931,000
Increase in cash surrender value of company owned life insurance	50,000	117,000	117,000
Proceeds from life insurance policies	$ 0		$ 0
Maximum [Member] | Private Equity Funds [Member]
Investment [Line Items]
Investment owned, percent of net assets	1.00%