Loans Receivable and Allowance for Loan Losses (Details 2) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Loans receivable and allowance for loan losses disclosures
30-59 Days Past Due	$ 114,328,000	$ 146,782,000
60-89 Days Past Due	39,641,000	37,637,000
Current	12,176,881,000	12,670,088,000
Impaired loans	393,677,000	346,906,000
Bankruptcy loans | Non-performing
Loans receivable and allowance for loan losses disclosures
30-59 Days Past Due	5,700,000
60-89 Days Past Due	1,200,000
Current	58,300,000
Loans which are less than 90 days past due	65,200,000
Loans discharged prior to 2012 included in loans which are less than 90 days past due	51,500,000
Impaired loans	90,000,000
Loans discharged prior to 2012 included in impaired loans	$ 69,900,000