Investments in Real Estate Subsidiaries - Schedule of Investments in SPEs Properties (Details) - a	Sep. 30, 2024	Dec. 31, 2023
White Rock Center | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	100.00%	100.00%
5916 W Loop 289 | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	100.00%	100.00%
Cityplace Tower | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	100.00%	100.00%
NexPoint Dominion Land, LLC | Undeveloped Land in Plano, Texas
Summary of Investment Holdings [Line Items]
Area of land (acre)	21.5
NexPoint Dominion Land, LLC | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	100.00%	100.00%
Dallas Hilton Garden Inn | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%
Addison Homewood Suites | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%
Plano Homewood Suites | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%
Las Colinas Homewood Suites | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%
St. Petersburg Marriott | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%
Hyatt Place Park City | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%
Bradenton Hampton Inn & Suites | Special Purpose Entities Directly Owned Companies
Summary of Investment Holdings [Line Items]
Effective ownership (as a percent)	54.00%