Business Segments (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2016		Jun. 30, 2015		Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net sales		$ 931,558		$ 889,541		$ 1,833,981	$ 1,754,822
Percent change in net sales		4.70%				4.50%
Gross profit		$ 567,520		533,911		$ 1,127,039	1,052,072
Percent change in gross profit		6.30%				7.10%
Operating profit		$ 282,685	[1]	279,091	[1]	$ 556,848	549,166
Percent change in operating profit		1.30%	[1]			1.40%
Long-lived assets		$ 115,563		126,961		$ 115,563	126,961
Percent change in long-lived assets						(9.00%)
Operating Segments [Member] | Medical And Scientific Imaging [Member]
Segment Reporting Information [Line Items]
Net sales		$ 340,585		302,262		$ 672,799	593,962
Percent change in net sales		12.70%				13.30%
Gross profit		$ 246,396		222,990		$ 493,293	438,316
Percent change in gross profit		10.50%				12.50%
Operating profit		$ 114,271	[1]	109,261	[1]	$ 228,727	217,040
Percent change in operating profit		4.60%	[1]			5.40%
Long-lived assets		$ 38,400		37,172		$ 38,400	37,172
Percent change in long-lived assets						3.30%
Operating Segments [Member] | RF Technology [Member]
Segment Reporting Information [Line Items]
Net sales		$ 288,761		255,558		$ 568,971	498,512
Percent change in net sales		13.00%				14.10%
Gross profit		$ 163,005		134,136		$ 323,370	264,182
Percent change in gross profit		21.50%				22.40%
Operating profit		$ 89,354	[1]	79,940	[1]	$ 178,120	153,917
Percent change in operating profit		11.80%	[1]			15.70%
Long-lived assets		$ 30,111		30,398		$ 30,111	30,398
Percent change in long-lived assets						(0.90%)
Operating Segments [Member] | Industrial Technology [Member]
Segment Reporting Information [Line Items]
Net sales		$ 178,627		186,467		$ 349,862	377,195
Percent change in net sales		(4.20%)				(7.20%)
Gross profit		$ 89,709		93,565		$ 175,729	188,807
Percent change in gross profit		(4.10%)				(6.90%)
Operating profit		$ 51,291	[1]	52,188	[1]	$ 98,050	110,085
Percent change in operating profit		(1.70%)	[1]			(10.90%)
Long-lived assets		$ 35,865		44,343		$ 35,865	44,343
Percent change in long-lived assets						(19.10%)
Operating Segments [Member] | Energy Systems And Controls [Member]
Segment Reporting Information [Line Items]
Net sales		$ 123,585		145,254		$ 242,349	285,153
Percent change in net sales		(14.90%)				(15.00%)
Gross profit		$ 68,410		83,220		$ 134,647	160,767
Percent change in gross profit		(17.80%)				(16.20%)
Operating profit		$ 27,769	[1]	37,702	[1]	$ 51,951	68,124
Percent change in operating profit		(26.30%)	[1]			(23.70%)
Long-lived assets		$ 11,187		15,048		$ 11,187	15,048
Percent change in long-lived assets						(25.70%)
Corporate [Member]
Segment Reporting Information [Line Items]
Unallocated corporate general and administrative expenses	[1]	$ 29,607		$ 27,117		$ 58,779	$ 50,296

[1] *Segment operating profit is before unallocated corporate general and administrative expenses. These expenses were $29,607 and $27,117 for the three months ended June 30, 2016 and 2015, respectively, and $58,779 and $50,296 for the six months ended June 30, 2016 and 2015, respectively.