Business Segment Information Business Combinations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Business Acquisition [Line Items]
Property, Plant and Equipment, Net	$ 386,409				$ 370,402				$ 386,409	$ 370,402
Revenues	390,249	355,215	342,707	318,639	377,760	328,283	312,425	188,980	1,406,810	1,207,448	1,257,733
Payments to Acquire Productive Assets									66,682	77,442	44,087
Assets	1,405,696				1,426,685				1,405,696	1,426,685
Restructuring Charges	(877)	1,164	99	258	779	(23)	105	341	644	1,202	4,848
Depreciation, Depletion and Amortization									62,906	54,389	56,218
Healthcare member [Member]
Business Acquisition [Line Items]
Restructuring Charges										1,020	3,839
Life Science Member [Member]
Business Acquisition [Line Items]
Restructuring Charges										190	555
Isomedix Member [Member]
Business Acquisition [Line Items]
Restructuring Charges										142
Healthcare and Life Sciences [Member]
Business Acquisition [Line Items]
Payments to Acquire Productive Assets									31,713	36,156	20,602
Assets	1,024,786				1,072,892				1,024,786	1,072,892
Depreciation, Depletion and Amortization									37,559	30,188	32,640
Isomedix Member [Member]
Business Acquisition [Line Items]
Payments to Acquire Productive Assets									34,943	41,271	23,454
Assets	378,506				352,153				378,506	352,153
Depreciation, Depletion and Amortization									25,324	24,183	23,553
Reportable Segment [Member]
Business Acquisition [Line Items]
Payments to Acquire Productive Assets									66,656	77,427	44,056
Assets	1,403,292				1,425,045				1,403,292	1,425,045
Depreciation, Depletion and Amortization									62,883	54,371	56,193
Corporate and Other member [Member]
Business Acquisition [Line Items]
Payments to Acquire Productive Assets									26	15	31
Assets	2,404				1,640				2,404	1,640
Depreciation, Depletion and Amortization									23	18	25
UNITED STATES
Business Acquisition [Line Items]
Revenues									1,057,461	882,281	949,637
International Member [Member]
Business Acquisition [Line Items]
Revenues									349,349	325,167	308,096
UNITED STATES
Business Acquisition [Line Items]
Property, Plant and Equipment, Net	331,590				318,110				331,590	318,110
International Member [Member]
Business Acquisition [Line Items]
Property, Plant and Equipment, Net	$ 54,819				$ 52,292				$ 54,819	$ 52,292