Fair Value Measurements - Schedule of Fair Value Measurements, Recurring (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Dec. 31, 2024	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities available-for-sale	$ 16,099	$ 17,323
Interest rate cap and swap agreements (included in Other assets)	8,964	31,860
Real estate loans held by consolidated securitization vehicles	1,013,273	584,134
Debt fund investments, at fair value	73,402	0
Interest rate cap and swap agreements (included in Other liabilities)	17,544	6,469
Senior obligations of consolidated securitization vehicles	1,013,273	567,487
Secured borrowing (included in Other liabilities)	$ 236,886	251,096
One Madison Avenue | National Pension Service of Korea / Hines Interest LP / International Investor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment in joint venture aggregate maximum ownership percentage	25.00%		25.00%
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities available-for-sale	$ 0	0
Interest rate cap and swap agreements (included in Other assets)	0	0
Real estate loans held by consolidated securitization vehicles	0	0
Debt fund investments, at fair value	0
Interest rate cap and swap agreements (included in Other liabilities)	0	0
Senior obligations of consolidated securitization vehicles	0	0
Secured borrowing (included in Other liabilities)	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities available-for-sale	16,099	17,323
Interest rate cap and swap agreements (included in Other assets)	8,964	31,860
Real estate loans held by consolidated securitization vehicles	995,054	584,134
Debt fund investments, at fair value	67,975
Interest rate cap and swap agreements (included in Other liabilities)	17,544	6,469
Senior obligations of consolidated securitization vehicles	995,054	567,487
Secured borrowing (included in Other liabilities)	0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities available-for-sale	0	0
Interest rate cap and swap agreements (included in Other assets)	0	0
Real estate loans held by consolidated securitization vehicles	18,219	0
Debt fund investments, at fair value	5,427
Interest rate cap and swap agreements (included in Other liabilities)	0	0
Senior obligations of consolidated securitization vehicles	18,219	0
Secured borrowing (included in Other liabilities)	236,886	$ 251,096
Level 3 | The Debt Investment Fund
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fund purchased	5,300
Unrealized gains on investments	$ 100