Commitments and Contingencies

Operating Leases

The Company leases office space in 49 cities in 25 countries. The terms of these office-related leases provide that the Company pay base rent and a share of operating expenses and real estate taxes in excess of defined amounts. These leases expire at various dates through 2026. The Company also leases certain computer equipment and cars, the terms of which are accounted for as operating leases. Rent expense, which includes the base rent, maintenance costs, operating expenses and real estate taxes, and the costs of equipment leases for the years ended December 31, 2018, 2017 and 2016, was $33.2 million, $32.2 million and $30.8 million, respectively.

Minimum future operating lease payments due in each of the next five years and thereafter are as follows:



2019	$	34,456
2020	31,808
2021	27,381
2022	23,445
2023	20,087
Thereafter	14,448
Total	$	151,625

The aggregate minimum future payments on office leases are $150.1 million. The Company has contractual arrangements to receive aggregate sublease income of $0.2 million related to certain leases that expire at various dates through 2019. This sublease income primarily relates to properties that were part of prior office consolidations and closings.

Certain leases provide for renewal options and payments of real estate taxes and other occupancy costs. In addition, certain leases contain rent escalation clauses that require additional rental amounts in later years of the term. Rent expense for leases with rent escalation clauses is recognized on a straight-line basis over the minimum lease term.

The Company has an obligation at the end of the lease term to return certain offices to the landlord in its original condition, which is recorded at fair value at the time the liability is incurred. The Company had $2.7 million and $2.9 million of asset retirement obligations as of December 31, 2018 and 2017, respectively, which are recorded within Other current liabilities and Other non-current liabilities in the Consolidated Balance Sheets.

Litigation

The Company has contingent liabilities from various pending claims and litigation matters arising in the ordinary course of the Company’s business, some of which involve claims for damages that are substantial in amount. Some of these matters are covered by insurance. Based upon information currently available, the Company believes the ultimate resolution of such claims and litigation will not have a material adverse effect on its financial condition, results of operations or liquidity.