(18)	Commitments

The Company has operating leases expiring on various dates through the year 2019. The leases are primarily for the rental of office space, office and laboratory equipment and vehicles. At December 31, 2013, future minimum commitments under non-cancelable operating lease arrangements were as follows:

Year ended December 31:
2014	$	968
2015		830
2016		539
2017		515
2018		442
2019 and thereafter		101
Total commitments	$	3,395

Total operating lease expense was $1,090, $815 and $644 for the years ended December 31, 2013, 2012 and 2011, respectively.

The Company is party to several unconditional purchase obligations resulting from contracts that contain legally binding provisions with respect to quantities, pricing and timing of purchases. The Company’s purchase obligations mainly include commitments to purchase utilities. At December 31, 2013, future commitments under these obligations were as follows:

Year ended December 31:
2014	$	2,171
2015		598
2016		-
2017		-
2018		-
Total commitments	$	2,769