Agency Securities, fixed rate securities, weighted average coupon.

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Amount of investment in debt security measured at amortized cost (held-to-maturity), investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and investment in debt security measured at fair value with change in fair value recognized in net income (trading).

+ References

No definition available.

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
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The aggregate amount of liabilities as of the balance sheet date for obligations incurred in connection with the entity's investments.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.15)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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- Definition

Amount of other-than-temporary impairment (OTTI) on investment in debt security, recognized in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 8A
-URI http://asc.fasb.org/extlink&oid=118954083&loc=SL6284422-111562

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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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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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-Name Accounting Standards Codification
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Investment In Securities - Additional Information (Details) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Debt securities	$ 7,991,138,000				$ 12,825,367,000	$ 7,991,138,000	$ 8,480,548,000
Securities, trading, at fair value	939,184,000				883,601,000	939,184,000
OTTI, Available-for-sale	0	$ 0	$ 0	$ (12,090,000)	0	(12,090,000)	(13,707,000)
TBA Agency Securities
Debt Securities, Available-for-sale [Line Items]
Securities, trading, at fair value	$ 933,420,000				1,006,280,000	933,420,000
Agency securities
Debt Securities, Available-for-sale [Line Items]
OTTI, Available-for-sale				$ (12,090,000)	$ 0		(13,707,000)
Agency Securities
Debt Securities, Available-for-sale [Line Items]
OTTI, Available-for-sale						$ (12,090,000)
Weighted average coupon rate	3.94%				3.76%	3.94%
Investment-related payables	$ 166,052,000				$ 358,712,000	$ 166,052,000
U.S. Treasury Securities
Debt Securities, Available-for-sale [Line Items]
Securities, trading, at fair value	98,646,000				0	98,646,000	$ 0
TBA Agency Securities
Debt Securities, Available-for-sale [Line Items]
Derivative assets (liabilities), net	$ 4,236,000				$ (592,000)	$ 4,236,000