(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, 2012, future minimum commitments under non-cancelable operating lease arrangements were as follows:

Year ended December 31:
2013	$	995
2014		846
2015		671
2016		502
2017		499
2018 and thereafter		539
Total commitments	$	4,052

Total operating lease expense was $815, $644 and $2,027 for the years ended December 31, 2012, 2011 and 2010, 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, 2012, future commitments under these obligations were as follows:

Year ended December 31:
2013	$	2,557
2014		1,708
2015		-
2016		-
2017		-
Total commitments	$	4,265