Commitments and Other Contingencies

We are committed under various operating lease agreements primarily related to office space and equipment. Generally, these leases include renewal provisions and rental payments, which may be adjusted for taxes, insurance and maintenance related to the property. Future minimum commitments under noncancellable operating leases are as follows (dollars in millions):



2017	$	214
2018	166
2019	102
2020	60
2021	45
Thereafter	201
	$	788

Total rent expense incurred under operating leases was approximately $324 million, $426 million and $536 million for the years ended December 31, 2016, 2015 and 2014, respectively. The future rental commitment table above does not include leases that are short-term in nature or can be cancelled with notice of less than three months.

Other Contingencies

We have a contractual residual value guarantee at December 31, 2016 of $28 million in “Other Non-Current Liabilities” on the accompanying Consolidated Balance Sheets related to certain leased equipment in our North America pressure pumping business.

We have supply contract related minimum purchase commitments and maintain a liability at December 31, 2016 of $155 million for expected penalties to be paid, of which $34 million is recorded in “Other Current Liabilities” and $121 million is recorded in “Other Non-Current Liabilities” on our Consolidated Balance Sheets.