The Company is involved from time to time in litigation on various matters, including disputes with tenants, disputes with vendors, employee disputes and disputes arising out of agreements to purchase or sell properties or joint ventures or disputes relating to state and local taxes. Given the nature of the Company’s business activities, these lawsuits are considered routine to the conduct of its business. The result of any particular lawsuit cannot be predicted, because of the very nature of litigation, the litigation process and its adversarial nature, and the jury system. The Company will establish reserves for specific legal proceedings when it determines that the likelihood of an unfavorable outcome is probable and when the amount of loss is reasonably estimable. The Company does not expect that the liabilities, if any, that may ultimately result from such legal actions will have a material adverse effect on the consolidated financial position, results of operations or cash flows of the Company.

Under certain mortgages, the Company has funded required leasing and capital reserve accounts for the benefit of the mortgage lenders with letters-of-credit. There were no associated letters-of-credit for a mortgage lender on December 31, 2018. Certain of the tenant rents at properties that secure these mortgage loans are deposited into the loan servicer’s depository accounts, which are used to fund debt service, operating expenses, capital expenditures and the escrow and reserve accounts, as necessary. Any excess cash is included in cash and cash equivalents.

As an owner of real estate, the Company is subject to various environmental laws of federal, state, and local governments. The Company’s compliance with existing laws has not had a material adverse effect on its financial condition and results of operations, and the Company does not believe it will have a material adverse effect in the future. However, the Company cannot predict the impact of unforeseen environmental contingencies or new or changed laws or regulations on its current Properties or on properties that the Company may acquire.

Future minimum rental payments under the terms of all non-cancellable ground leases under which the Company is the lessee are expensed on a straight-line basis regardless of when payments are due. The Company’s ground leases have remaining lease terms ranging from 10 to 66 years. Minimum future rental payments on non-cancelable leases at December 31, 2018 are as follows (in thousands):

Year	Minimum Rent
2019	$	1,222
2020		1,222
2021		1,222
2022		1,222
2023		1,222
Thereafter		55,689
Total	$	61,799

The Company obtained ground tenancy rights related to three properties in Philadelphia, Pennsylvania, which provide for contingent rent participation by the lessor in certain capital transactions and net operating cash flows of the properties after certain returns are achieved by the Company. Such amounts, if any, will be reflected as contingent rent when incurred. The leases also provide for payment by the Company of certain operating costs relating to the land, primarily real estate taxes. The above schedule of future minimum rental payments does not include any contingent rent amounts or any reimbursed expenses.

On April 2, 2015, the Company purchased 618 Market Street in Philadelphia, Pennsylvania. The allocated purchase price included contingent consideration of $2.0 million payable to the seller upon commencement of development. The liability was recorded at a fair value of $1.6 million and will accrete through interest expense to $2.0 million over the expected period until development is commenced. The fair value of this contingent consideration was determined using a probability weighted discounted cash flow model. The significant inputs to the discounted cash flow model were the discount rate and weighted probability scenarios. As the inputs are unobservable, the Company determined the inputs used to value this liability fall within Level 3 for fair value reporting. As of December 31, 2018, the liability had accreted to $1.9 million. As there were no significant changes to the inputs, the liability remains within Level 3 for fair value reporting.

As of December 31, 2018, the Company’s unconsolidated real estate ventures had aggregate indebtedness of $370.3 million. These loans are generally mortgage or construction loans, most of which are non-recourse to the Company, except for customary carve-outs. As of December 31, 2018, the loans for which there is recourse to the Company consist of the following: (i) a $0.3 million payment guarantee on a loan with a $3.8 million outstanding principal balance, provided to PJP VII and (ii) up to a $41.3 million payment guarantee on a $150.0 million construction loan provided to 4040 Wilson. In addition, during construction undertaken by real estate ventures, including 4040 Wilson, the Company has provided and expects to continue to provide cost overrun and completion guarantees, with rights of contribution among partners or members in the real estate ventures, as well as customary environmental indemnities and guarantees of customary exceptions to nonrecourse provisions in loan agreements.

On October 13, 2017, the Company acquired a leasehold interest in the office building known as The Bulletin Building, in Philadelphia, Pennsylvania. See Note 3, “Real Estate Investments,” for further information. In connection with the acquisition, the Company is required to spend no less than $8.0 million in capital improvements to the property. As of December 31, 2018, $1.2 million of the funding related to this requirement had been met. The Company estimates that it will incur $37.3 million in excess of this funding requirement and expects to complete the redevelopment of The Bulletin Building during the second quarter of 2020 at an estimated aggregate cost of $83.1 million, inclusive of the acquisition cost of $37.8 million.

Also on October 13, 2017, the Company acquired a leasehold interest in the land parcel at 3001 Market Street in Philadelphia, Pennsylvania (“Drexel Square”). During the fourth quarter of 2017, the Company broke ground on the construction of a public park on the site, marking the commencement of construction of its Schuylkill Yards Project with Drexel. Under the terms of the Development Agreement with Drexel, the Company has until July 2019 to complete development of Drexel Square. If the Company is unable to complete such development within this timeframe, it may be subject to damages under the Development Agreement. As of December 31, 2018, the project is substantially complete.

During the fourth quarter of 2017, in connection with the Schuylkill Yards Project, the Company entered into a neighborhood engagement program and, as of December 31, 2018, had $2.7 million of future contractual obligations. In addition, the Company estimates $0.6 million of potential additional contributions for which the Company is not currently contractually obligated.

As part of the Company’s September 2004 acquisition of a portfolio of properties from The Rubenstein Company (which the Company refers to as the “TRC acquisition”), the Company acquired its interest in Two Logan Square, a 708,844 square foot office building in Philadelphia, primarily through its ownership of a second and third mortgage secured by this property. This property is consolidated, as the borrower is a variable interest entity and the Company, through its ownership of the second and third mortgages, is the primary beneficiary. The Company currently does not expect to take title to Two Logan Square until, at the earliest, on or about August 2020. If the Company takes fee title to Two Logan Square upon foreclosure of its mortgage, the Company has agreed to pay an unaffiliated third party that holds a residual interest in the fee owner of this property an amount equal to $2.9 million. On the TRC acquisition date, the Company recorded a liability of $0.7 million and this amount will accrete up to $2.9 million through January 2020. As of December 31, 2018, the Company had a balance of $2.7 million for this liability in its consolidated balance sheets.

As part of the Company’s 2006 merger with Prentiss Properties Trust (“Prentiss”), the 2004 TRC acquisition and several of our other transactions, the Company agreed not to sell certain of the properties it acquired in transactions that would trigger taxable income to the former owners. In the case of the TRC acquisition, the Company agreed not to sell acquired properties in non-exempt transactions for periods up to 15 years from the date of the TRC acquisition as follows at December 31, 2018: One Logan Square, Two Logan Square and Radnor Corporate Center (January 2020). The Company subsequently agreed to extend the no-sale period applicable to

Two Logan Square to on or about August 2020. In the Prentiss acquisition, the Company assumed the obligation of Prentiss not to sell Concord Airport Plaza before March 2018. The Company’s agreements generally provide that it may dispose of the subject properties only in transactions that qualify as tax-free exchanges under Section 1031 of the Internal Revenue Code or in other tax deferred transactions. On February 2, 2017, the Company completed the disposition of Concord Airport Plaza in a transaction that qualified as a tax-free exchange under Section 1031 of the Internal Revenue Code. See Note 3, “Real Estate Investments,” for further information. If the Company were to sell a restricted property before the expiration of the restricted period in a non-exempt transaction, the Company may be required to make significant payments to the parties who sold the applicable property on account of tax liabilities attributed to them. Similarly, as part of the 2013 acquisition of substantially all of the equity interests in the partnerships that own One and Two Commerce Square, the Company agreed, for the benefit of affiliates of the holder of the 1% residual ownership interest in these properties, to not sell these two properties in certain taxable transactions prior to October 20, 2021 without the holder’s consent.

As part of the Company’s acquisition of properties from time to time in tax-deferred transactions, the Company has agreed to provide certain of the prior owners of the acquired properties with the right to guarantee the Company’s indebtedness. If the Company were to seek to repay the indebtedness guaranteed by the prior owner before the expiration of the applicable agreement, the Company would be required to provide the prior owner an opportunity to guaranty qualifying replacement debt. These debt maintenance agreements may limit the Company’s ability to refinance indebtedness on terms favorable to the Company. As part of our 2013 acquisition of substantially all of the equity interests in the partnerships that own One and Two Commerce Square, the Company agreed, for the benefit of affiliates of the holder of the 1% residual ownership interest in these properties, to maintain qualifying mortgage debt through October 20, 2021, in the amounts of not less than $125.0 million on One Commerce Square and $100.0 million on Two Commerce Square. Similarly, the Company has agreements in place with other contributors of assets that obligate it to maintain debt available for them to guaranty.

The Company invests in its properties and regularly incurs capital expenditures in the ordinary course of business to maintain the properties. The Company believes that such expenditures enhance its competitiveness. The Company also enters into construction, utility and service contracts in the ordinary course of business which may extend beyond one year. These contracts typically provide for cancellation with insignificant or no cancellation penalties.