Restructuring and Asset Impairment Charges Employee Separation and Other Cash Charges (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Restructuring Reserve [Roll Forward]
Beginning balance	$ 1,960	$ 6,193
Period charges	0	769
Payments through June 30	(555)	(1,742)
Ending balance June 30	1,405	5,220
South America [Member]
Restructuring Reserve [Roll Forward]
Beginning balance	183	1,073
Period charges	0	0
Payments through June 30	(18)	(80)
Ending balance June 30	165	993
Specialty products [Member]
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Period charges	0	0
Payments through June 30	0	0
Ending balance June 30	0	0
Other regions [Member]
Restructuring Reserve [Roll Forward]
Beginning balance	1,777	5,120
Period charges	0	769
Payments through June 30	(537)	(1,662)
Ending balance June 30	$ 1,240	$ 4,227