Mortgage Loans (Policies)	3 Months Ended
Mar. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Financing Receivable, Held-for-investment [Policy Text Block]	Loans Held for Investment When we acquire mortgage loans that we have the ability and the intent to hold for the foreseeable future or until maturity, we classify the loans as HFI. When we consolidate a securitization trust, we recognize the loans underlying the trust in our condensed consolidated balance sheets. The trusts do not have the ability to sell mortgage loans and the use of such loans is limited exclusively to the settlement of obligations of the trusts. Therefore, mortgage loans acquired when we have the intent to securitize via consolidated trusts are generally classified as HFI in our condensed consolidated balance sheets both prior to and subsequent to their securitization. We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and allowance for loan losses. We define the amortized cost of HFI loans as unpaid principal balance and accrued interest receivable, net of unamortized premiums, discounts, and other cost basis adjustments. For purposes of our condensed consolidated balance sheets, we present accrued interest receivable separately from the amortized cost of our loans held for investment. We recognize interest income on HFI loans on an accrual basis using the effective yield method over the contractual life of the loan, including the amortization of any deferred cost basis adjustments, such as the premium or discount at acquisition, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured. We report the amortized cost of HFI loans for which we have not elected the fair value option at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and accrued interest receivable. For purposes of our condensed consolidated balance sheet, we present accrued interest receivable separately from the amortized cost of our loans held for investment
Financing Receivable, Held-for-sale [Policy Text Block]	Loans Held for Sale When we acquire mortgage loans that we intend to sell or securitize via trusts that will not be consolidated, we classify the loans as held for sale (“HFS”). We report the carrying value of HFS loans at the lower of cost or fair value. Any excess of an HFS loan’s cost over its fair value is recognized as a valuation allowance, with changes in the valuation allowance recognized as “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We recognize interest income on HFS loans on an accrual basis, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured. Purchased premiums, discounts and other cost basis adjustments on HFS loans are deferred upon loan acquisition, included in the cost basis of the loan, and not amortized. We determine any lower of cost or fair value adjustment on HFS loans at an individual loan level. For nonperforming loans transferred from held for investment (“HFI”) to HFS, based upon a change in our intent, we record the loans at the lower of cost or fair value on the date of transfer. When the fair value of the nonperforming loan is less than its amortized cost, we record a write-off against the allowance for loan losses in an amount equal to the difference between the amortized cost basis and the fair value of the loan. If the amount written off upon transfer exceeds the allowance related to the transferred loan, we record the excess in provision for credit losses. If the amounts written off are less than the allowance related to the loans, we recognize a benefit for credit losses. Nonperforming loans include both seriously delinquent and reperforming loans, which are loans that were previously delinquent but are performing again because payments on the mortgage loan have become current with or without the use of a loan modification plan. Single-family seriously delinquent loans are loans that are 90 days or more past due or in the foreclosure process. Multifamily seriously delinquent loans are loans that are 60 days or more past due. In the event that we reclassify a performing loan from HFI to HFS, based upon a change in our intent, the allowance for loan losses previously recorded on the HFI mortgage loan is reversed through earnings at the time of reclassification. The mortgage loan is reclassified into HFS at its amortized cost basis and a valuation allowance is established to the extent that the amortized cost basis of the loan exceeds its fair value. The initial recognition of the valuation allowance and any subsequent changes are recorded as a gain or loss in “Investment gains (losses), net.” We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.
Troubled Debt Restructurings [Policy Text Block]	A modification to the contractual terms of a loan that results in granting a concession to a borrower experiencing financial difficulties is considered a TDR. In addition to formal loan modifications, we also engage in other loss mitigation activities with troubled borrowers, which include repayment plans and forbearance arrangements, both of which represent informal agreements with the borrower that do not result in the legal modification of the loan’s contractual terms. We account for theseinformal restructurings as a TDR if we defer more than three missed payments. We also classify loans to certain borrowers who have received bankruptcy relief as TDRs. Our current TDR accounting described herein will be temporarily impacted by our election to account for certain eligible loan modifications under the COVID-19 Relief granted pursuant to the CARES Act.

Mortgage Loans (Policies)

3 Months Ended

Mar. 31, 2020

SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]

Financing Receivable, Held-for-investment [Policy Text Block]

Loans Held for Investment

When we acquire mortgage loans that we have the ability and the intent to hold for the foreseeable future or until maturity, we classify the loans as HFI. When we consolidate a securitization trust, we recognize the loans underlying the trust in our condensed consolidated balance sheets. The trusts do not have the ability to sell mortgage loans and the use of such loans is limited exclusively to the settlement of obligations of the trusts. Therefore, mortgage loans acquired when we have the intent to securitize via consolidated trusts are generally classified as HFI in our condensed consolidated balance sheets both prior to and subsequent to their securitization.

We report the carrying value of HFI loans at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and allowance for loan losses. We define the amortized cost of HFI loans as unpaid principal balance and accrued interest receivable, net of unamortized premiums, discounts, and other cost basis adjustments. For purposes of our condensed consolidated balance sheets, we present accrued interest receivable separately from the amortized cost of our loans held for investment. We recognize interest income on HFI loans on an accrual basis using the effective yield method over the contractual life of the loan, including the amortization of any deferred cost basis adjustments, such as the premium or discount at acquisition, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured.

We report the amortized cost of HFI loans for which we have not elected the fair value option at the unpaid principal balance, net of unamortized premiums and discounts, other cost basis adjustments, and accrued interest receivable. For purposes of our condensed consolidated balance sheet, we present accrued interest receivable separately from the amortized cost of our loans held for investment

Financing Receivable, Held-for-sale [Policy Text Block]

Loans Held for Sale

When we acquire mortgage loans that we intend to sell or securitize via trusts that will not be consolidated, we classify the loans as held for sale (“HFS”). We report the carrying value of HFS loans at the lower of cost or fair value. Any excess of an HFS loan’s cost over its fair value is recognized as a valuation allowance, with changes in the valuation allowance recognized as “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income. We recognize interest income on HFS loans on an accrual basis, unless we determine that the ultimate collection of contractual principal or interest payments in full is not reasonably assured. Purchased premiums, discounts and other cost basis adjustments on HFS loans are deferred upon loan acquisition, included in the cost basis of the loan, and not amortized. We determine any lower of cost or fair value adjustment on HFS loans at an individual loan level.

For nonperforming loans transferred from held for investment (“HFI”) to HFS, based upon a change in our intent, we record the loans at the lower of cost or fair value on the date of transfer. When the fair value of the nonperforming loan is less than its amortized cost, we record a write-off against the allowance for loan losses in an amount equal to the difference between the amortized cost basis and the fair value of the loan. If the amount written off upon transfer exceeds the allowance related to the

transferred loan, we record the excess in provision for credit losses. If the amounts written off are less than the allowance related to the loans, we recognize a benefit for credit losses.

Nonperforming loans include both seriously delinquent and reperforming loans, which are loans that were previously delinquent but are performing again because payments on the mortgage loan have become current with or without the use of a loan modification plan. Single-family seriously delinquent loans are loans that are 90 days or more past due or in the foreclosure process. Multifamily seriously delinquent loans are loans that are 60 days or more past due.

In the event that we reclassify a performing loan from HFI to HFS, based upon a change in our intent, the allowance for loan losses previously recorded on the HFI mortgage loan is reversed through earnings at the time of reclassification. The mortgage loan is reclassified into HFS at its amortized cost basis and a valuation allowance is established to the extent that the amortized cost basis of the loan exceeds its fair value. The initial recognition of the valuation allowance and any subsequent changes are recorded as a gain or loss in “Investment gains (losses), net.”

We report the carrying value of HFS loans at the lower of cost or fair value and record valuation changes in “Investment gains (losses), net” in our condensed consolidated statements of operations and comprehensive income.

Troubled Debt Restructurings [Policy Text Block]

A modification to the contractual terms of a loan that results in granting a concession to a borrower experiencing financial difficulties is considered a TDR. In addition to formal loan modifications, we also engage in other loss mitigation activities with troubled borrowers, which include repayment plans and forbearance arrangements, both of which represent informal agreements with the borrower that do not result in the legal modification of the loan’s contractual terms. We account for theseinformal restructurings as a TDR if we defer more than three missed payments. We also classify loans to certain borrowers who have received bankruptcy relief as TDRs. Our current TDR accounting described herein will be temporarily impacted by our election to account for certain eligible loan modifications under the COVID-19 Relief granted pursuant to the CARES Act.