Property, Plant & Equipment (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property, plant and equipment	$ 139,885,000		$ 137,996,000
Accumulated depreciation	(68,673,000)		(63,893,000)
Property, plant and equipment — net	71,212,000		74,103,000
Capital expenditures in progress	1,516,000		2,331,000
Capitalized interest expense	0	$ 2,000
Commitments for capital expenditures in progress	$ 1,013,000		$ 1,102,000