Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 724,872	$ 699,871	$ 1,435,938	$ 1,345,180
Gross Profit	397,608	377,063	788,801	727,159
Operating Profit	178,784	163,970	349,088	305,970
Long-lived assets	5,502,181		5,502,181		5,319,417
Unallocated corporate general and administrative expenses	17,334	13,726	33,909	26,946
Industrial Technology
Segment Reporting Information [Line Items]
Net sales	203,944	183,455	399,080	353,437
Percent change in Net Sales	11.2		12.9
Gross Profit	102,770	92,068	201,433	177,782
Percent change in Gross Profit	11.6		13.3
Operating Profit	62,076	51,729	119,583	97,918
Percent change in Operating Profit	20.0		22.1
Long-lived assets	43,096	41,343	43,096	41,343
Percent change in Long-lived assets	4.2
Energy Systems And Controls
Segment Reporting Information [Line Items]
Net sales	154,737	145,750	303,339	275,383
Percent change in Net Sales	6.2		10.2
Gross Profit	86,135	80,412	166,543	150,558
Percent change in Gross Profit	7.1		10.6
Operating Profit	40,202	37,704	75,859	66,748
Percent change in Operating Profit	6.6		13.6
Long-lived assets	18,892	17,868	18,892	17,868
Percent change in Long-lived assets	5.7
Medical And Scientific Imaging
Segment Reporting Information [Line Items]
Net sales	150,921	151,078	313,732	296,365
Percent change in Net Sales	(0.1)		5.9
Gross Profit	96,212	95,006	202,398	186,260
Percent change in Gross Profit	1.3		8.7
Operating Profit	35,679	35,352	79,041	70,389
Percent change in Operating Profit	0.9		12.3
Long-lived assets	44,314	48,261	44,314	48,261
Percent change in Long-lived assets	(8.2)
RF Technology
Segment Reporting Information [Line Items]
Net sales	215,270	219,588	419,787	419,995
Percent change in Net Sales	(2.0)		0.0
Gross Profit	112,491	109,577	218,427	212,559
Percent change in Gross Profit	2.7		2.8
Operating Profit	58,161	52,911	108,514	97,861
Percent change in Operating Profit	9.9		10.9
Long-lived assets	$ 28,639	$ 31,047	$ 28,639	$ 31,047
Percent change in Long-lived assets	(7.8)