Loans Receivable (Details) (USD $)	1 Months Ended		12 Months Ended											1 Months Ended		1 Months Ended
	May 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Secured and unsecured loans	Dec. 21, 2012 Secured and unsecured loans	Dec. 31, 2013 Secured loans loan	Dec. 31, 2012 Secured loans loan	Dec. 31, 2013 Unsecured loans loan	Dec. 31, 2012 Unsecured loans loan	Dec. 31, 2013 Loans Receivable Maturing 2017	Jul. 31, 2013 Senior Secured Portion Sold Eight Percent Loan Receivable Maturing in 2017 [Member]	Jul. 25, 2013 Eight Percent Loan Receivable Maturing in 2017 [Member]	Jul. 31, 2013 Eight Percent Loan Receivable Maturing in 2017 [Member]	May 31, 2013 Twelve Percent Loan Receivable Maturing in 2017 [Member]	Dec. 31, 2012 Twelve Percent Loan Receivable Maturing in 2017 [Member]
Accounts, Notes, Loans and Financing Receivable
Loans receivable, net		$ 697,100,000	$ 414,700,000	$ 697,100,000
Proceeds from loans receivable			325,518,000	43,219,000	220,179,000	102,300,000	37,600,000
Number of secured loans repaid								7	3	3	4
Gain (Loss) on Loans, Net			5,100,000									0
Payments to Acquire Mortgage Backed Securities (MBS) categorized as Available-for-sale	21,000,000
Available-for-sale Securities, Amortized Cost Basis			21,700,000
Available-for-sale Securities, fair value			21,500,000
Loans receivable, aggregate principal amount		375,000,000												182,100,000			50,000,000
Loans receivable, weighted average interest rate		8.00%
Loans Receivable, Interest Rate													4.50%		9.40%		12.00%
Proceeds from Sale of Loans Receivable														66,400,000		25,000,000
Proceeds From Prepayment Penalties And Fees, Loans Receivable			$ 1,500,000