Residential Mortgage Securities and MSR-Related Assets (Sale of MBS) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	$ 195,333	$ 179,328	$ 404,796	$ 198,690
Gains/(Losses)	7,710	7,429	32,319	16,246
Agency MBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	103,345	75,306	103,345	75,306
Gains/(Losses)	(2,272)	(3,787)	(2,272)	(3,787)
Non-Agency MBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	70,818	0	196,912	19,362
Gains/(Losses)	8,823	0	26,976	8,817
CRT securities
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	21,170	104,022	104,539	104,022
Gains/(Losses)	$ 1,159	$ 11,216	$ 7,615	$ 11,216

Net gain (loss) resulting from the sales of securitized, pay-through debt securities collateralized by real estate mortgage loans (mortgages).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13(h))
-URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260

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- Definition

Amount of cash inflow from sale of investment in mortgage-backed security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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