Goodwill and Other Intangible Assets - Carrying Value of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Goodwill [Roll Forward]
Balance at period start	$ 71,131
Addition upon acquisition of IAL	1,689
Balance at period end	72,820
Energy Chemistry Technologies [Member]
Goodwill [Roll Forward]
Balance at period start	36,318
Addition upon acquisition of IAL	0
Balance at period end	36,318
Consumer and Industrial Chemistry Technologies [Member]
Goodwill [Roll Forward]
Balance at period start	19,480
Addition upon acquisition of IAL	0
Balance at period end	19,480
Teledrift [Member]
Goodwill [Roll Forward]
Balance at period start	15,333
Addition upon acquisition of IAL	0
Balance at period end	15,333
Production Technologies [Member]
Goodwill [Roll Forward]
Balance at period start	0
Addition upon acquisition of IAL	1,689
Balance at period end	$ 1,689