Business Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 segment division	Jun. 30, 2011	Dec. 31, 2011
Business Segment Information
Number of operating segments			5
Number of divisions			5
Revenue:
Product and service revenue between reportable segments	$ (2.3)	$ (4.8)	$ (4.8)	$ (7.6)
Total revenue	420.7	401.2	826.3	758.2
Operating Income (Loss):
Total operating income	22.1	38.7	56.5	64.4
Interest and other income (expense), net	(2.8)	(5.7)	(10.3)	(10.7)
Income before income taxes and noncontrolling interest in consolidated subsidiaries	19.3	33.0	46.2	53.7
Assets:
Total assets	1,750.1		1,750.1		1,710.5
Scientific Instruments
Revenue:
Total revenue	397.0	377.9	775.1	713.7
Operating Income (Loss):
Total operating income	23.2	38.3	58.3	66.0
Assets:
Total assets	1,692.1		1,692.1		1,675.0
Energy and Supercon Technologies
Revenue:
Total revenue	26.0	28.1	56.0	52.1
Operating Income (Loss):
Total operating income	(0.7)	0.4	(0.1)	(0.3)
Assets:
Total assets	119.2		119.2		104.4
Corporate, eliminations and other
Operating Income (Loss):
Total operating income	(0.4)		(0.8)	(1.3)
Assets:
Total assets	$ (61.2)		$ (61.2)		$ (68.9)