Note 8 - Fair Value of Financial Instruments - Schedule of Carrying Values and Fair Values of Financial Assets and Liabilities Recorded at Fair Value on a Recurring Basis (Details) - USD ($) | Mar. 31, 2021 | Dec. 31, 2020 | Feb. 11, 2020 |
Common stock, at fair value | $ 45,460,000 | $ 44,626,000 | |
Carrying value | 38,923,000 | $ 38,984,000 | |
Reported Value Measurement [Member] | | | |
Cash and cash equivalents | | | $ 302 |
Loans, held-for-investment, net | | | 22,127 |
Accrued interest and dividends | | | 3,616 |
Assets, Fair Value Disclosure | | | 2,719,837 |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | | | 2,539,724 |
Reported Value Measurement [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Bonds payable held in variable interest entities, at fair value | | | 1,655,960 |
Reported Value Measurement [Member] | Mortgages [Member] | | | |
Loans, held-for-investment, net | | | 863,564 |
Reported Value Measurement [Member] | Mortgages [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Loans, held-for-investment, net | | | $ 1,790,228 |
Fair Value, Recurring [Member] | | | |
Cash and cash equivalents | 14,917,000 | | |
Restricted Cash | 570,000 | | |
Loans, held-for-investment, net | 153,382,000 | | |
Common stock, at fair value | 45,460,000 | | |
Accrued interest and dividends | 5,646,000 | | |
Carrying value | 38,923,000 | | |
Other assets | 3,384,000 | | |
Assets, Fair Value Disclosure | 5,948,917,000 | | |
Secured financing agreements, net | 869,421,000 | | |
Master repurchase agreements | 162,168,000 | | |
Unsecured Notes | 35,025,000 | | |
Accounts payable and other accrued liabilities | 3,807,000 | | |
Accrued interest payable | 2,791,000 | | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 5,569,983,000 | | |
Fair Value, Recurring [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Bonds payable held in variable interest entities, at fair value | 4,496,771,000 | | |
Fair Value, Recurring [Member] | Mortgages [Member] | | | |
Loans, held-for-investment, net | 904,317,000 | | |
Fair Value, Recurring [Member] | Mortgages [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Loans, held-for-investment, net | 4,782,318,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | | | |
Cash and cash equivalents | 14,917,000 | | |
Restricted Cash | 570,000 | | |
Loans, held-for-investment, net | | | |
Common stock, at fair value | | | |
Accrued interest and dividends | 5,646,000 | | |
Carrying value | | | |
Other assets | 3,384,000 | | |
Assets, Fair Value Disclosure | 24,517,000 | | |
Secured financing agreements, net | | | |
Master repurchase agreements | | | |
Unsecured Notes | | | |
Accounts payable and other accrued liabilities | 3,807,000 | | |
Accrued interest payable | 2,791,000 | | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 6,598,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Bonds payable held in variable interest entities, at fair value | | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgages [Member] | | | |
Loans, held-for-investment, net | | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgages [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Loans, held-for-investment, net | | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | | | |
Cash and cash equivalents | | | |
Restricted Cash | | | |
Loans, held-for-investment, net | | | |
Common stock, at fair value | | | |
Accrued interest and dividends | | | |
Carrying value | 38,923,000 | | |
Other assets | | | |
Assets, Fair Value Disclosure | 4,821,241,000 | | |
Secured financing agreements, net | | | |
Master repurchase agreements | | | |
Unsecured Notes | | | |
Accounts payable and other accrued liabilities | | | |
Accrued interest payable | | | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 4,496,771,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Bonds payable held in variable interest entities, at fair value | 4,496,771,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgages [Member] | | | |
Loans, held-for-investment, net | | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgages [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Loans, held-for-investment, net | 4,782,318,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | | | |
Cash and cash equivalents | | | |
Restricted Cash | | | |
Loans, held-for-investment, net | 153,382,000 | | |
Common stock, at fair value | 45,460,000 | | |
Accrued interest and dividends | | | |
Carrying value | | | |
Other assets | | | |
Assets, Fair Value Disclosure | 1,103,159,000 | | |
Secured financing agreements, net | 869,421,000 | | |
Master repurchase agreements | 162,168,000 | | |
Unsecured Notes | 35,025,000 | | |
Accounts payable and other accrued liabilities | | | |
Accrued interest payable | | | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 1,066,614,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Bonds payable held in variable interest entities, at fair value | | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgages [Member] | | | |
Loans, held-for-investment, net | 904,317,000 | | |
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgages [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Loans, held-for-investment, net | | | |
Fair Value, Recurring [Member] | Reported Value Measurement [Member] | | | |
Cash and cash equivalents | 14,917,000 | | |
Restricted Cash | 570,000 | | |
Loans, held-for-investment, net | 153,637,000 | | |
Common stock, at fair value | 45,460,000 | | |
Accrued interest and dividends | 5,646,000 | | |
Carrying value | 38,923,000 | | |
Other assets | 3,384,000 | | |
Assets, Fair Value Disclosure | 5,960,203,000 | | |
Secured financing agreements, net | 839,687,000 | | |
Master repurchase agreements | 162,168,000 | | |
Unsecured Notes | 35,025,000 | | |
Accounts payable and other accrued liabilities | 3,807,000 | | |
Accrued interest payable | 2,791,000 | | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | 5,540,249,000 | | |
Fair Value, Recurring [Member] | Reported Value Measurement [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Bonds payable held in variable interest entities, at fair value | 4,496,771,000 | | |
Fair Value, Recurring [Member] | Reported Value Measurement [Member] | Mortgages [Member] | | | |
Loans, held-for-investment, net | 915,348,000 | | |
Fair Value, Recurring [Member] | Reported Value Measurement [Member] | Mortgages [Member] | Variable Interest Entity, Primary Beneficiary [Member] | | | |
Loans, held-for-investment, net | $ 4,782,318,000 | | |