PROPERTY, PLANT AND EQUIPMENT

3 Months Ended

Mar. 31, 2016

Property, Plant and Equipment [Abstract]

Property, plant and equipment, net of accumulated depreciation, consists of the following (in thousands):



	March 31, 2016			December 31, 2015
Land	$	5,603		$	5,773
Buildings and improvements	169,400			165,322
Equipment	136,599			135,998
Office furniture and equipment	14,975			14,548
Construction in-progress	30,238			25,659
Property, plant and equipment, gross	356,815			347,300

Less: Accumulated depreciation	(137,415		)	(133,144		)
Property, plant and equipment, net	$	219,400		$	214,156

Depreciation expense was $6.3 million and $5.4 million for the three months ended March 31, 2016 and March 31, 2015, respectively.

Unpaid vendor invoices relating to purchases of property, plant and equipment of $4.5 million and $1.3 million, which were accrued as of March 31, 2016 and March 31, 2015, respectively, have been excluded from the purchase of property, plant, and equipment and the change in accounts payable and accrued expenses in the Company’s consolidated statements of cash flows.