20. Leased Assets

We and certain of our subsidiaries lease drilling rigs, office space and other assets for varying periods under contractual obligations accounted for as operating leases. Operating lease expenses for drilling rigs used to drill development wells and successful exploration wells are capitalized. At December 31, 2017, future minimum rental payments applicable to non‑cancelable operating leases with remaining terms of one year or more (other than oil and gas property leases) are as follows (in millions):

2018	$	387
2019	376
2020	130
2021	71
2022	70
Remaining years	276
Total Minimum Lease Payments		1,310
Less: Income from subleases	99
Net Minimum Lease Payments	$	1,211

Rental expense was as follows:

	2017		2016		2015
	(In millions)
Total rental expense	$	123	$	106	$	167
Less: Income from subleases	10		5		10
Net Rental Expense	$	113	$	101	$	157