Fair Value of Financial Instruments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real estate owned	$ 152,356,000	$ 80,503,000	$ 28,026,000
Other real estate, fair value	$ 175,800,000	$ 91,100,000
Term Notes backed by MSR Related Collateral
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assumptions, Weighted Average Yield to Maturity	6.12%
Minimum | Term Notes backed by MSR Related Collateral
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assumption, Implied Yields	5.80%
Maximum | Term Notes backed by MSR Related Collateral
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assumption, Implied Yields	6.60%
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative credit risk valuation adjustment, derivative liabilities	$ 0