Stock-based Compensation (Performance Conditioned AO LTIP Units & Vornado Stock Options Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds received from exercise of employee share options and other	$ 5,862	$ 6,903	$ 7,309
Vornado stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (years)	4 years
Stock options expiration term	10 years
Grants in period, weighted average grant date fair value (usd per share)	$ 12.28	$ 16.64	$ 18.42
Proceeds received from exercise of employee share options and other	$ 3,516	$ 5,495	$ 5,927
Exercises in period, intrinsic value	$ 859	$ 18,954	25,820
Performance Conditioned AO LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (usd per share)		$ 64.48
Threshold percentage to satisfy performance based condition	110.00%
Threshold period to satisfy performance based condition	20 days
Grant-date fair value		$ 8,983
AO LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options expiration term	10 years
Grant-date fair value	$ 4,319	$ 3,429	$ 3,484
Threshold level, percent	100.00%
Special allocation	10.00%
Special distribution, percent	10.00%

Amount of cash inflow from exercise of option under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value at grant date for equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

No definition available.

+ Details

Name:	vno_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue1
Namespace Prefix:	vno_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Special Allocation

+ References

No definition available.

+ Details

Name:	vno_SharebasedCompensationArrangementbySharebasedPaymentAwardSpecialAllocation
Namespace Prefix:	vno_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Threshold Level

+ References

No definition available.

+ Details

Name:	vno_SharebasedCompensationArrangementbySharebasedPaymentAwardThresholdLevel
Namespace Prefix:	vno_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Special Distribution, Percent

+ References

No definition available.

+ Details

Name:	vno_SpecialDistributionPercent
Namespace Prefix:	vno_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold Percentage to Satisfy Performance Based Condition

+ References

No definition available.

+ Details

Name:	vno_ThresholdPercentagetoSatisfyPerformanceBasedCondition
Namespace Prefix:	vno_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold Period to Satisfy Performance Based Condition

+ References

No definition available.

+ Details

Name:	vno_ThresholdPeriodtoSatisfyPerformanceBasedCondition
Namespace Prefix:	vno_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=vno_PerformanceConditionedAOLTIPUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=vno_AOLTIPUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: