Property, Plant and Equipment

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

5 Property, Plant and Equipment

Property, plant and equipment consist of the following (in thousands):

		December 31,
		2017		2016
Land and land improvements		$	37,525	$	35,720
Buildings and leasehold improvements			294,219		274,021
Production and other equipment			484,475		438,604
Construction in progress			22,140		20,204
	Total property, plant and equipment		838,359		768,549
Less: accumulated depreciation and amortization			(489,081)		(431,431)
	Property, plant and equipment, net	$	349,278	$	337,118

During 2017, 2016 and 2015, the Company retired and disposed of approximately $15 million, $15 million and $29 million of property, plant and equipment, respectively, most of which was fully depreciated and no longer in use. Gains on disposal were immaterial for the years ended December 31, 2017 and 2016.

In February 2018, the Company’s Board of Directors approved expanding its chemistry synthesis operations. The Company anticipates spending an estimated $215 million to build and equip this new state-of-the-art manufacturing facility, which will be paid for with existing cash and investments. The Company does not expect to issue any debt in relation to this expansion.