Financing Agreements (Borrowings Under Repurchase Agreement And Associated Assets Pledged as Collateral) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets Sold under Agreements to Repurchase [Line Items]
Fair value of securities pledged as collateral under repurchase agreements	$ 3,800,000	$ 4,200,000
Non-mark-to-market financing secured by residential whole loans at carrying value
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	794,634	906,466
Fair value of securities pledged as collateral under repurchase agreements	$ 1,313,629	$ 1,500,100
Weighted average haircut (percent)	38.62%	38.36%
Non-mark-to-market financing secured by residential whole loans at fair value
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	$ 239,654	$ 249,659
Fair value of securities pledged as collateral under repurchase agreements	$ 427,234	$ 430,183
Weighted average haircut (percent)	43.89%	42.69%
Non-mark-to-market financing secured by real estate owned
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	$ 6,995	$ 3,088
Fair value of securities pledged as collateral under repurchase agreements	$ 16,183	$ 7,441
Weighted average haircut (percent)	56.41%	59.65%
Mark-to-market financing agreements secured by residential whole loans at carrying value
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	$ 732,442	$ 839,594
Fair value of securities pledged as collateral under repurchase agreements	$ 1,168,394	$ 1,297,243
Weighted average haircut (percent)	34.39%	32.57%
Mark-to-market financing agreements secured by residential whole loans at fair value
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	$ 236,321	$ 273,959
Fair value of securities pledged as collateral under repurchase agreements	$ 468,279	$ 501,570
Weighted average haircut (percent)	48.71%	39.02%
Mark-to-market financing agreements secured by securities at fair value
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	$ 200,746	$ 213,915
Fair value of securities pledged as collateral under repurchase agreements	$ 350,115	$ 399,999
Weighted average haircut (percent)	40.06%	41.16%
Mark-to-market financing agreements secured by real estate owned
Assets Sold under Agreements to Repurchase [Line Items]
Carrying Value	$ 10,778	$ 10,609
Fair value of securities pledged as collateral under repurchase agreements	$ 37,108	$ 22,525
Weighted average haircut (percent)	51.76%	55.25%
Loan Securitization
Assets Sold under Agreements to Repurchase [Line Items]
Fair value of securities pledged as collateral under repurchase agreements	$ 36,300	$ 141,900

The weighted average percentage amount by which the collateral value is contractually required to exceed the loan amount on the Company's repurchase agreements borrowings.

No definition available.

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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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- Definition

The fair value, as of the date of each statement of financial position presented, of securities which are owned but transferred to serve as collateral for the payment of repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
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- Definition

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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