Commitments and Contingencies Rental expense, primarily for office premises, amounted to $87.5 million , $87.3 million and $85.9 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The approximate minimum rental commitments for 2018 and thereafter under non-cancelable leases in effect at December 31, 2017 were as follows (in thousands): 2018 $ 85,484 2019 73,763 2020 64,221 2021 47,107 2022 35,535 Thereafter 64,042 $ 370,152 On March 13, 2014, Plaintiff Leonor Rodriguez, on her own behalf and on behalf of a putative class of allegedly similarly situated individuals, filed a complaint against the Company in the Superior Court of California, San Diego County. The complaint alleges that a putative class of current and former employees of the Company working in California since March 13, 2011 were denied compensation for the time they spent interviewing with clients of the Company as well as performing activities related to the interview process. Rodriguez seeks recovery on her own behalf and on behalf of the putative class in an unspecified amount for this allegedly unpaid compensation. Rodriguez also seeks recovery of an unspecified amount for the alleged failure of the Company to provide her and the putative class with accurate wage statements. Rodriguez also seeks an unspecified amount of other damages, attorneys fees, and statutory penalties, including but not limited to statutory penalties on behalf of herself and other allegedly aggrieved employees as defined by Californias Labor Code Private Attorney General Act (PAGA). On October 10, 2014, the Court granted a motion by the Company to compel all of Rodriguezs claims, except the PAGA claim, to individual arbitration. At this stage of the litigation, it is not feasible to predict the outcome of or a range of loss, should a loss occur, from this proceeding and, accordingly, no amounts have been provided in the Companys Financial Statements. The Company believes it has meritorious defenses to the allegations and the Company inten