Commitments, Off-Balance Sheet Arrangements and Contingent Liabilities (Details Textuals) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Loss contingency reserve	$ 21,000,000	$ 22,000,000
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Abstract]
Standby letters of credit Fair value	4,009,000	3,811,000
Carrying value of investments	34,000,000	35,000,000
Commitments under unconsolidated projects	17,000,000	18,000,000
Residential mortgage loans sold with recourse risk	61,000,000	79,000,000
Residential mortgage loans sold with credit recourse risk	295,000,000	321,000,000
Corporations potential risk exposure	2,000,000
Corporations liability for reinsurance losses	1,000,000	8,000,000
Loss Contingency, Settlement Agreement, Consideration	13,000,000
From insurer as a contribution to settlement amount	2,500,000
From insurer as a contribution to defense costs	1,500,000
Loans sold to outside investors original amount	15,900,000,000
Loans sold to outside investors remaining outstanding amount	6,900,000,000
Loans repurchased under make whole requests	2,000,000	3,000,000
Loss reimbursements under make whole requests	$ 2,000,000	$ 4,000,000