Leases

We lease some of our office space under non-cancelable operating leases with third parties and sublease office space to third parties. Some of our lease agreements contain renewal options and escalation clauses based on increases in property taxes and building operating costs.

As of December 31, 2018, future minimum lease payments under non-cancelable operating leases (net of sublease income) are as follows:



	Gross Lease Commitments		Sublease Income		Net Lease Commitments
	(in millions)
Year ending December 31:
2019	$	80	$	5	$	75
2020	74		5		69
2021	66		4		62
2022	48		4		44
2023	45		3		42
Thereafter	347		2		345
Total future minimum lease payments	$	660	$	23	$	637

Rent expense for operating leases (net of sublease income of $5 million in 2018, $3 million in 2017, and $4 million in 2016) was $82 million in 2018, $83 million in 2017, and $78 million in 2016.

In February 2016, the FASB issued ASU 2016-02, “Leases.” We adopted this new guidance on January 1, 2019. See “Leases,” of “Recent Accounting Pronouncements,” of Note 2, “Summary of Significant Accounting Policies,” for further discussion.