Residential Whole Loans (Purchased Credit Impaired Loans - Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Allowance for loan losses	$ 968,000	$ 330,000	$ 990,000	$ 1,165,000
Provisions/(reversal of provisions) for loan losses		(660,000)	(175,000)
Purchased credit impaired loans
Financing Receivable, Impaired [Line Items]
Allowance for loan losses	968,000	330,000	$ 990,000
Provisions/(reversal of provisions) for loan losses	$ 638,000	$ (660,000)