Commitments and Contingencies and Derivative Financial Instruments

Commitments Under Operating Leases

We lease certain of our facilities and equipment under operating leases with net aggregate future lease payments at September 28, 2018, payable as follows (in thousands):



In fiscal years,
2019	$	215,375
2020	187,228
2021	158,781
2022	135,991
2023	115,614
Thereafter	344,120
	1,157,109
Amounts representing sublease income	(19,443		)
	$	1,137,666

We recognize rent expense, inclusive of landlord concessions and tenant allowances, over the lease term on a straight-line basis. We also recognize rent expense on a straight-line basis for leases containing fixed escalation clauses and rent holidays. Contingent rentals are included in rent expense as incurred. Operating leases relating to many of our major offices generally contain renewal options and provide for additional rental based on escalation in operating expenses and real estate taxes.

The following table presents rent expense and sublease income offsetting the Company’s rent expense for the years ended September 28, 2018, September 29, 2017 and September 30, 2016 (in thousands):



	For the Years Ended
	September 28, 2018			September 29, 2017			September 30, 2016
Rent expense	$	217,550		$	145,344		$	151,539
Sublease income	(5,514		)	(7,052		)	(7,212		)
Net rent expense	$	212,036		$	138,292		$	144,327

Synthetic Lease Guarantee

We are party to a synthetic lease agreement involving certain real and personal property located in Houston, Texas that we use in our operations. A synthetic lease is a type of off-balance sheet transaction which provides us with certain tax and other financial benefits. Significant terms of the lease are as follows:



End of lease term	2025
End of term purchase option (in thousands)	$	76,950
Residual value guarantee (in thousands)	$	62,412

The Company refinanced the synthetic lease agreement effective July 28, 2015 with a 10-year term. The new lease agreement continues to gives us the right to request an extension of the lease term. We may also assist the owner in selling the property at the end of the lease term, the proceeds from which would be used to reduce our residual value guarantee. The minimum lease payments required by the lease agreement is included in the above lease payment schedule. We have determined that the estimated Fair Value of the aforementioned financial guarantee was not significant at September 28, 2018.

Derivative Financial Instruments

In situations where our operations incur contract costs in currencies other than their functional currency, we attempt to have a portion of the related contract revenues denominated in the same currencies as the costs. In those situations where revenues and costs are transacted in different currencies, we sometimes enter into foreign exchange contracts in order to limit our exposure to fluctuating foreign currencies. The Company does not currently have exchange rate sensitive instruments that would have a material effect on our consolidated financial statements or results of operations.

Letters of Credit

At September 28, 2018, the Company had issued and outstanding approximately $446.6 million in LOCs and $870.3 million in surety bonds. Of the outstanding LOC amount, $2.5 million has been issued under the Revolving Credit Facility and $444.1 million are issued under separate, committed and uncommitted letter-of-credit facilities.