5. Lease Obligations

The Company has warehouse, office, furniture, fixtures, and equipment leases, which expire at various dates through 2033. Under the lease agreements, the Company is also obligated to pay property taxes, insurance, and maintenance costs.

Certain leases contain renewal options. Future minimum rental commitments for non-cancelable operating leases as of December 31, 2018 were as follows:

The Company recognizes rental expense on a straight-line basis. Rental expense, which is included in selling, general, and administrative expenses within the Company’s consolidated statements of income, was $61.1 million, $56.2 million, and $53.4 million for the years ended December 31, 2018, 2017, and 2016, respectively.

There was no material property, plant, and equipment under capital leases included in property, plant, and equipment on the accompanying consolidated balance sheets as of December 31, 2018 and 2017.