All of the Company’s leases are classified as operating leases. The Company's Lease income is comprised of both fixed and variable income. Fixed and in-substance fixed lease income includes stated amounts per the lease contract, which are primarily related to base rent, and in some cases stated amounts for common area maintenance (“CAM”), real estate taxes, and insurance. Income for these amounts is recognized on a straight-line basis.

Variable lease income includes the following two main items in the lease contracts:

(i) Recoveries from tenants represents amounts tenants are contractually obligated to reimburse the Company for the tenants’ portion of actual Recoverable Costs incurred. Generally the Company’s leases provide for the tenants to reimburse the Company based on the tenants’ share of the actual costs incurred in proportion to the tenants’ share of leased space in the property.

(ii) Percentage rent represents amounts billable to tenants based on the tenants' actual sales volume in excess of levels specified in the lease contract.

The following table provides a disaggregation of lease income recognized as either fixed or variable lease income based on the criteria specified in ASC Topic 842:

(in thousands)	Three months ended March 31,
	2021			2020
Operating lease income
Fixed and in-substance fixed lease income	$	196,054			204,943
Variable lease income		64,067			64,668
Other lease related income, net:
Above/below market rent and tenant rent inducement amortization, net		5,996			12,880
Uncollectible straight line rent		(2,035	)		(3,902	)
Uncollectible amounts billable in lease income		2,275			(4,052	)
Total lease income	$	266,357			274,537

Lease income for operating leases with fixed payment terms is recognized on a straight-line basis over the expected term of the lease for all leases for which collectibility is considered probable at the commencement date. At lease commencement, the Company generally expects that collectibility is probable due to the Company’s credit checks on tenants and other creditworthiness analysis undertaken before entering into a new lease; therefore, income from most operating leases is initially recognized on a straight-line basis. For operating leases in which collectibility of Lease income is not considered probable, Lease

income is recognized on a cash basis and all previously recognized straight-line rent receivables are reversed in the period in which the Lease income is determined not to be probable of collection. In addition to the lease-specific collectibility assessment performed under Topic 842, the Company also recognizes a general reserve, as a reduction to Lease income, for its portfolio of operating lease receivables which are not expected to be fully collectible based on the Company’s historical collection experience.

During 2020, in response to the pandemic and the resulting entry into agreements for rent concessions between tenants and landlords, the FASB issued interpretive guidance relating to the accounting for lease concessions provided as a result of COVID-19. In this guidance, entities could elect not to apply lease modification accounting with respect to such lease concessions, and instead, treat the concession as if it was a part of the existing contract and therefore continue to recognize the deferred rents in the period originally billed subject to separate collectibility assessments under Topic 842. This guidance is only applicable to COVID-19 related lease concessions that do not result in a substantial increase in the right of the lessor or the obligations of the lessee. The Company has elected to treat concessions that satisfy this criteria as though the concession was part of the existing contract and therefore not treated like a lease modification.

During the three months ended March 31, 2021, the Company experienced higher uncollectible lease income on current period billings compared to the three months ended March 31, 2020 when the Company was only seeing the first indications of the pandemic’s impact on tenants. However, this higher uncollectible lease income was offset by collections of prior period billings from our cash basis tenants resulting in a net positive impact of $2.3 million.

The Company continues to negotiate with certain remaining tenants, which may result in further rent concessions as determined necessary and appropriate. Collectibility of these concessions generally includes consideration of the tenants’ business performance, ability to sustain their business in the current environment, as well as an assessment of their credit worthiness and ability to repay such amounts in the future.

The following table represents the components of Tenant and other receivables in the accompanying Consolidated Balance Sheets:

(in thousands)	March 31, 2021		December 31, 2020
Tenant receivables	$	21,630	$	39,658
Straight-line rent receivables		87,180		86,615
Other receivables⁽¹⁾		18,645		17,360
Total tenant and other receivables	$	127,455	$	143,633