Goodwill and Other Intangible Assets (Goodwill) (Details) (USD $)	9 Months Ended	12 Months Ended
	Oct. 02, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Goodwill [Roll Forward]
Balance at beginning of period	$ 234,189,000	$ 306,888,000	$ 234,189,000
Acquisition		259,839,000	65,112,000
Foreign currency translation adjustments		(22,256,000)	7,587,000
Balance at end of period		544,471,000	306,888,000	234,189,000
Accumulated impairment [Abstract]
Goodwill impairment, net	0	0	0	37,504,000
Magnetic Technologies [Member]
Goodwill [Roll Forward]
Balance at beginning of period	0	0	0
Acquisition		220,801,000	0
Foreign currency translation adjustments		(19,221,000)	0
Balance at end of period		201,580,000	0
Advanced Materials [Member]
Goodwill [Roll Forward]
Balance at beginning of period	103,326,000	103,326,000	103,326,000
Acquisition		0	0
Foreign currency translation adjustments		0	0
Balance at end of period		103,326,000	103,326,000
Specialty Chemicals [Member]
Goodwill [Roll Forward]
Balance at beginning of period	130,863,000	138,211,000	130,863,000
Acquisition		39,038,000	0
Foreign currency translation adjustments		(2,949,000)	7,348,000
Balance at end of period		174,300,000	138,211,000	130,863,000
Accumulated impairment [Abstract]
Accumulated goodwill impairment charges		46,300,000
Goodwill impairment, net				37,500,000
Battery Technologies Member
Goodwill [Roll Forward]
Balance at beginning of period	0	65,351,000	0
Acquisition		0	65,112,000
Foreign currency translation adjustments		(86,000)	239,000
Balance at end of period		$ 65,265,000	$ 65,351,000