Investments (Details Textuals 7) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of Mortgage Loans	0	4
Carrying Value after Specific Valuation Allowance	$ 0	$ 13
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Mortgage Loans	0	0
Carrying Value after Specific Valuation Allowance	$ 0
Residential
Financing Receivable, Modifications [Line Items]
Number of Mortgage Loans	0	0