The Company leases real estate to its tenants primarily under leases that are predominately classified as operating leases. The Company's leases generally provide for rent escalations throughout the lease terms. Rents that are fixed are recognized on a straight-line basis over the lease term. Base rent escalations that include a variable component are recognized upon the occurrence of the specified event as defined in the Company's lease agreements. Many of the Company's leasing arrangements include options to extend the lease, which are not included in the minimum lease terms unless it is reasonably certain to be exercised. Straight-line rental revenue is subject to an evaluation for collectibility, and the Company records a direct write-off against rental revenue if collectibility of these future rents is not probable. For the years ended December 31, 2019, 2018 and 2017 , the Company recognized straight-line rental revenue, net of write-offs of $13.6 million (of which $3.0 million has been classified within discontinued operations), $10.2 million (of which $5.5 million has been classified within discontinued operations) and $4.3 million (of which $6.7 million has been classified within discontinued operations), respectively. The Company recognized straight-line write-offs for the years ended December 31, 2019 and 2017 of $1.4 million (of which $1.2 million has been classified within discontinued operations) and $9.0 million , respectively. There were no straight-line write-offs recognized during the year ended December 31, 2018 . Most of the Companys lease contracts are triple-net leases, which require the tenants to make payments directly to third parties for lessor costs (such as property taxes and insurance) associated with the properties. In accordance with Topic 842, the Company does not include these payments made by the lessees to third parties in rental revenue or property operating expenses. In certain situations, the Company pays these lessor costs directly to third-parties and the tenants reimburse the Company. In accordance with Topic 842, these payments are presented on a gross basis in rental revenue and property operating expense. During the year ended December 31, 2019 , the Company recognized $6.9 million related to the gross up of these reimbursed expenses which are included in rental revenue and property operating expenses. Certain of the Company's leases, particularly at its entertainment districts, require the tenants to make payments to the Company for property related expenses such as common area maintenance. The Company has elected to combine these non-lease components with the lease components in rental revenue. For the years ended December 31, 2019, 2018 and 2017 , the non-lease components included in rental revenue totaled $16.0 million , $15.3 million and $15.5 million , respectively. In addition, most of the Company's tenants are subject to additional rents if gross revenues of the properties exceed certain thresholds defined in the lease agreements (percentage rents). Percentage rents are recognized at the time when specific triggering events occur as provided by the lease agreement. Rental revenue included percentage rents of $15.0 million , $10.7 million and $7.8 million for the years ended December 31, 2019, 2018 and 2017 , respectively. The Company regularly evaluates the collectibility of its receivables on a lease by lease basis. The evaluation primarily consists of reviewing past due account balances and considering such factors as the credit quality of the Company's tenants, historical trends of the tenant and/or other debtor, current economic conditions and changes in customer payment terms. The Company suspends revenue recognition when the collectibility of lease receivables or future lease payments are no longer probable and records a direct write-off of the receivable to rental revenue. Certain reclassifications have been made to the 2017 and 2018 presentations to conform to the 2019 presentation related to the Company's former presentation of the allowance for doubtful accounts.