Debt - Repurchase Agreements, Real Estate Securities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Assets Sold under Agreements to Repurchase [Line Items]
Amount Outstanding	$ 234,524	$ 252,543
Accrued Interest	2,886	4,958
Real estate securities, available for sale, measured at fair value, amortized cost of $509,745 and $387,294 as of March 31, 2020 and December 31, 2019, respectively	441,160	386,316
Secured Debt \| U.S. Bank National Association \| Tranche C
Assets Sold under Agreements to Repurchase [Line Items]
Real estate securities, available for sale, measured at fair value, amortized cost of $509,745 and $387,294 as of March 31, 2020 and December 31, 2019, respectively	89,100	68,500
Revolving Credit Facility
Assets Sold under Agreements to Repurchase [Line Items]
Amount Outstanding	496,880	394,359
Accrued Interest	2,568	1,957
Collateral Pledged	$ 609,776	$ 454,301
Interest Rate	2.33%	2.79%
Days to Maturity	13 days	16 days
Revolving Credit Facility \| JP Morgan Securities LLC
Assets Sold under Agreements to Repurchase [Line Items]
Amount Outstanding	$ 159,879	$ 83,353
Accrued Interest	595	124
Collateral Pledged	$ 202,688	$ 93,500
Interest Rate	2.21%	2.53%
Days to Maturity	11 days	20 days
Revolving Credit Facility \| Wells Fargo Securities, LLC
Assets Sold under Agreements to Repurchase [Line Items]
Amount Outstanding	$ 159,924	$ 178,304
Accrued Interest	955	1,199
Collateral Pledged	$ 190,623	$ 209,873
Interest Rate	2.32%	2.94%
Days to Maturity	12 days	11 days
Revolving Credit Facility \| Barclays Capital Inc.
Assets Sold under Agreements to Repurchase [Line Items]
Amount Outstanding	$ 79,047	$ 40,720
Accrued Interest	365	221
Collateral Pledged	$ 106,965	$ 47,475
Interest Rate	2.28%	2.81%
Days to Maturity	17 days	23 days
Revolving Credit Facility \| Citigroup Global Markets, Inc.
Assets Sold under Agreements to Repurchase [Line Items]
Amount Outstanding	$ 98,030	$ 91,982
Accrued Interest	653	413
Collateral Pledged	$ 109,500	$ 103,453
Interest Rate	2.60%	2.69%
Days to Maturity	16 days	19 days

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Weighted average interest rate of debt outstanding.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for repurchase agreements, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

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