Summary of Significant Accounting Policies - Narrative (Details)		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2020 USD ($) d facility	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) d facility property	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) property
Variable Interest Entities
Assets of consolidated VIEs	[1]	$ 2,023,322,000		$ 2,023,322,000		$ 2,141,207,000
Liabilities of consolidated VIEs	[1]	1,506,185,000		1,506,185,000		$ 1,473,703,000
Finance Lease Obligations
Finance leases for equipment		$ 3,500,000		3,500,000
Payments of finance lease obligations				$ 300,000	$ 300,000
Weighted average interest rate (percent)		6.20%		6.20%
Remaining lease term (years)		2 years 10 months 24 days		2 years 10 months 24 days
Identified Intangibles
Amortization expense for in-place leases and deferred costs				$ 900,000	7,300,000
Acquisition Fees and Expenses
Acquisition fee and expense cap		6.00%		6.00%
Days notice required for lease termination | d		30		30
Variable lease revenues		$ 4,000,000.0	$ 4,100,000	$ 8,200,000	8,100,000
Concession period (days)				90 days
Repayment period (months)				12 months
Payments deferred		3,900,000		$ 3,900,000
Investments in Unconsolidated Ventures
Impairment loss		91,437,000	10,146,000	91,437,000	10,146,000
Impairment recognized				0
Impairment of affiliate properties				37,400,000
Income Taxes
Deferred tax asset		16,000,000.0		16,000,000.0
Income tax expense		14,000	$ 15,000	28,000	$ 21,000
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entities
VIE carrying value		$ 231,100,000		$ 231,100,000
Peregrine
Finance Lease Obligations
Number of properties held for sale | property				1		1
Investments in Unconsolidated Ventures
Impairment loss				$ 700,000
Winterfell
Investments in Unconsolidated Ventures
Impairment loss				$ 70,800,000
Properties | facility		8		8
Aqua
Investments in Unconsolidated Ventures
Impairment loss				$ 19,900,000
Griffin-American
Investments in Unconsolidated Ventures
Impairment of affiliate properties				34,100,000
Eclipse
Investments in Unconsolidated Ventures
Impairment of affiliate properties				2,900,000
Trilogy
Investments in Unconsolidated Ventures
Impairment of affiliate properties				600,000
Leases, Acquired-in-Place
Identified Intangibles
In-place lease value, gross		$ 130,000,000.0		130,000,000.0
In-place lease value, accumulated amortization		(124,500,000)		(124,500,000)
Variable Interest Entity, Primary Beneficiary | Operating Real Estate
Variable Interest Entities
Assets of consolidated VIEs		557,100,000		557,100,000
Variable Interest Entity, Primary Beneficiary | Mortgage Notes Payable
Variable Interest Entities
Liabilities of consolidated VIEs		$ 461,100,000		$ 461,100,000

[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 June 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.”