NOTE M — LEASES

Rent expense under operating leases was approximately $47.3 million, $48.1 million, and $50.1 million, for the years ended December 31, 2017, 2016 and 2015, respectively, which was included within “Other operating costs” and “General and administrative expenses” in our consolidated statements of operations and comprehensive loss. Sublease rental income is not material. The net book value of office equipment under capital leases was approximately $0.7 million and $0.8 million at December 31, 2017 and 2016, respectively. Equipment capital lease obligations are included in long-term debt as a part of “Financing leases and other” in Note N - “Long-Term Debt.”

Future minimum rental payments, by year and in the aggregate, under operating and financing obligations with terms of one year or more at December 31, 2017 are as follows:

(in thousands)	Operating Leases		Capital Leases

2018	$	38,567	$	343
2019	29,888		198
2020	21,418		121
2021	14,721		50
2022	9,417		—
Thereafter	11,903		—

Total	$	125,914	$	712

Future minimum rental payments, by year and in the aggregate, under operating and financing obligations with terms of one year or more at December 31, 2016 are as follows:

(in thousands)	Operating Leases		Capital Leases

2017	$	39,581	$	467
2018	32,507		268
2019	25,192		121
2020	17,226		39
2021	11,556		—
Thereafter	16,147		—

Total	$	142,209	$	895