LEASES

The Company leases certain land, buildings and equipment under noncancellable operating leases that expire at various dates through 2036. Capital leases as of December 31, 2016, are not considered material. Many of the building leases obligate the Company to pay real estate taxes, insurance and certain maintenance costs, and contain multiple renewal provisions, exercisable at the Company's option. Leases that contain predetermined fixed escalations of the minimum rentals are recognized in rental expense on a straight-line basis over the lease term. Cash or rent abatements received upon entering into certain operating leases are also recognized on a straight-line basis over the lease term.

At December 31, 2016, the approximate future minimum lease payments for all operating leases were as follows (in thousands of dollars):



Year	Future Minimum Lease Payments
2017	$	59,045
2018	45,504
2019	32,616
2020	15,358
2021	10,333
Thereafter	15,469
Total minimum payments required	178,325
Less amounts representing sublease income	(4,063		)
	$	174,262

Rent expense was $81 million for 2016 and $77 million for 2015 and 2014, respectively. These amounts are net of sublease income of $2 million for each 2016, 2015 and 2014.