Investments in Unconsolidated Ventures - Assets and Liabilities (Details) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Operating real estate, net		$ 1,571,696						$ 1,571,696		$ 1,700,218
Other assets		9,561						9,561		14,489
Total assets	[1]	2,007,962						2,007,962		2,141,207
Total liabilities	[1]	1,505,915						1,505,915		1,473,703
Equity		502,047	$ 517,137	$ 654,454	$ 693,360	$ 706,922	$ 726,119	502,047	$ 693,360	667,504	$ 744,374
Total liabilities and equity		2,007,962						2,007,962		2,141,207
Total revenues		67,755			72,778			209,954	220,271
Net income (loss)		(18,158)	$ (139,995)	$ (12,547)	(14,697)	$ (17,460)	$ (18,669)	(170,700)	(50,826)
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Schedule of Equity Method Investments [Line Items]
Operating real estate, net		3,360,236						3,360,236		3,566,586
Other assets		1,106,302						1,106,302		1,053,433
Total assets		4,466,538						4,466,538		4,620,019
Total liabilities		3,359,633						3,359,633		3,257,970
Equity		1,106,905						1,106,905		1,362,049
Total liabilities and equity		4,466,538						4,466,538		$ 4,620,019
Total revenues		986,221			977,874			315,560	320,978
Net income (loss)		$ (241,754)			$ (44,048)			$ (3,398)	$ (24,665)

[1] Represents the consolidated assets and liabilities of NorthStar Healthcare Income Operating Partnership, LP (the “Operating Partnership”). The Operating Partnership is a consolidated variable interest entity (“VIE”), of which the Company is the sole general partner and owns approximately 99.99%. As of September 30, 2020, the Operating Partnership includes $0.6 billion and $0.5 billion of assets and liabilities, respectively, of certain VIEs that are consolidated by the Operating Partnership. Refer to Note 2, “Summary of Significant Accounting Policies.”