Mortgage Banking Activities (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Net market valuation gains (losses) recorded	$ (230,731)	$ 56,046
Other income	4,188	19,257	$ 13,070
Mortgage Banking Activities, Net	78,472	87,266	59,566
Residential Mortgage Banking Activities, Net
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Other income	(6,652)	1,735	2,567
Mortgage Banking Activities, Net	3,721	47,743	59,623
Residential Mortgage Banking Activities, Net \| Residential loans, held-for-sale at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Changes in fair value of assets	41,284	63,527	21,808
Residential Mortgage Banking Activities, Net \| Trading securities
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Changes in fair value of assets	(4,535)	0	0
Residential Mortgage Banking Activities, Net \| Risk management derivatives, net
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Changes in fair value of risk management derivatives	(26,376)	(17,519)	35,248
Business Purpose Mortgage Banking
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Other income	18,642	16,205	0
Mortgage Banking Activities, Net	74,751	39,523	(57)
Business Purpose Mortgage Banking \| Risk management derivatives, net
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Changes in fair value of risk management derivatives	(21,403)	1,796	(510)
Business Purpose Mortgage Banking \| Single-family rental loans, held-for-sale
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Changes in fair value of assets	82,510	17,004	453
Business Purpose Mortgage Banking \| Bridge loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Changes in fair value of assets	$ (4,998)	$ 4,518	$ 0

Increase (Decrease) in Fair Value Adjustments on Assets

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- Definition

The net income attributable to mortgage banking activities. This includes market valuations related to residential and commercial loans, Sequoia IOs, and mortgage banking derivatives, as well as realized gains or losses associated with mortgage loan sales.

+ References

No definition available.

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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

Amount of unrealized gain (loss) related to the fair value of price risk derivatives designated as fair value hedging instruments, as offset by the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 50
-Paragraph 4C
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- Definition

Amount of increase (decrease) of investment in debt and equity securities, measured at fair value with changes in fair value recognized in net income.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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Amount of revenue and income classified as other.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
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