Goodwill (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of changes in the carrying value of goodwill

Changes in the carrying amount of goodwill for each reporting unit are as follows (in thousands):

	Energy Chemistry Technologies		Consumer and Industrial Chemistry Technologies		Total
Balance at December 31, 2015:
Goodwill	$	36,318	$	19,480	$	55,798
Accumulated impairment losses	—		—		—
Goodwill balance, net	36,318		19,480		55,798
Activity during the year 2016:
Goodwill impairment recognized	—		—		—
Acquisition goodwill recognized	862		—		862
Balance at December 31, 2016:
Goodwill	37,180		19,480		56,660
Accumulated impairment losses	—		—		—
Goodwill balance, net	37,180		19,480		56,660
Activity during the year 2017:
Goodwill impairment recognized	—		—		—
Acquisition goodwill recognized	—		—		—
Balance at December 31, 2017:
Goodwill	37,180		19,480		56,660
Accumulated impairment losses	—		—		—
Goodwill balance, net	$	37,180	$	19,480	$	56,660