Significant Accounting Policies (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended
	Dec. 31, 2012	Jun. 30, 2013 Debt and Preferred Equity Investments Held to Maturity	Jun. 30, 2012 Debt and Preferred Equity Investments Held to Maturity	Jun. 30, 2013 Debt and Preferred Equity Investments Held to Maturity	Jun. 30, 2012 Debt and Preferred Equity Investments Held to Maturity	Jun. 30, 2012 Debt and Preferred Equity Investments Held for Sale	Jun. 30, 2012 Debt and Preferred Equity Investments Held for Sale
Reserve for Possible Credit Losses
Loan loss reserves	$ 3,000	$ 0	$ 0	$ 0	$ 3,000
Recoveries recorded	$ 2,436					$ 0	$ 2,400