Business Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 segment division	Sep. 30, 2011	Dec. 31, 2011
Business Segment Information
Number of operating segments			4
Number of divisions			4
Revenue:
Product and service revenue between reportable segments	$ (3.5)	$ (3.9)	$ (8.3)	$ (11.5)
Total revenue	447.8	418.4	1,274.1	1,176.6
Operating Income (Loss):
Total operating income	60.3	37.5	116.8	101.9
Interest and other income (expense), net	(2.7)	1.9	(13.0)	(8.8)
Income before income taxes and noncontrolling interest in consolidated subsidiaries	57.6	39.4	103.8	93.1
Assets:
Total assets	1,800.0		1,800.0		1,710.5
Scientific Instruments
Revenue:
Total revenue	408.9	394.6	1,184.0	1,108.3
Operating Income (Loss):
Total operating income	48.0	41.3	106.3	107.3
Assets:
Total assets	1,739.4		1,739.4		1,675.0
Energy and Supercon Technologies
Revenue:
Total revenue	42.4	27.7	98.4	79.8
Operating Income (Loss):
Total operating income	14.4	(3.3)	13.4	(3.6)
Assets:
Total assets	127.2		127.2		104.4
Corporate, eliminations and other
Operating Income (Loss):
Total operating income	(2.1)	(0.5)	(2.9)	(1.8)
Assets:
Total assets	$ (66.6)		$ (66.6)		$ (68.9)