Investment in Loans (Schedule of Consumer Mortgage Loans) (Details) (Details) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 1,026,983
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	184,171
Premium (Discount)	6,912
Amortized Cost	191,083
Gains	2,623
Losses	(1,591)
Fair Value	$ 192,115
Life (Years)	285 days
Delinquency (Days)	3 days