Business Segments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net sales		$ 1,134,671	$ 931,558	$ 2,220,976	$ 1,833,981
Percent change in net sales		21.80%		21.10%
Gross profit		$ 705,650	567,520	$ 1,373,264	1,127,039
Percent change in gross profit		24.30%		21.80%
Operating profit	[1]	$ 331,989	282,685	$ 624,615	556,848
Percent change in operating profit	[1]	17.40%		12.20%
Long-lived assets		$ 167,694	115,563	$ 167,694	115,563
Percent change in long-lived assets		45.10%		45.10%
Operating Segments [Member] | Medical & Scientific Imaging [Member]
Segment Reporting Information [Line Items]
Net sales		$ 350,764	340,585	$ 698,999	672,799
Percent change in net sales		3.00%		3.90%
Gross profit		$ 254,028	246,396	$ 505,958	493,293
Percent change in gross profit		3.10%		2.60%
Operating profit	[1]	$ 121,315	114,271	$ 241,108	228,727
Percent change in operating profit	[1]	6.20%		5.40%
Long-lived assets		$ 45,255	38,400	$ 45,255	38,400
Percent change in long-lived assets		17.90%		17.90%
Operating Segments [Member] | RF Technology [Member]
Segment Reporting Information [Line Items]
Net sales		$ 460,497	288,761	$ 890,116	568,971
Percent change in net sales		59.50%		56.40%
Gross profit		$ 279,735	163,005	$ 531,213	323,370
Percent change in gross profit		71.60%		64.30%
Operating profit	[1]	$ 119,558	89,354	$ 208,542	178,120
Percent change in operating profit	[1]	33.80%		17.10%
Long-lived assets		$ 80,103	30,111	$ 80,103	30,111
Percent change in long-lived assets		166.00%		166.00%
Operating Segments [Member] | Industrial Technology [Member]
Segment Reporting Information [Line Items]
Net sales		$ 192,867	178,627	$ 376,271	349,862
Percent change in net sales		8.00%		7.50%
Gross profit		$ 98,167	89,709	$ 191,318	175,729
Percent change in gross profit		9.40%		8.90%
Operating profit	[1]	$ 58,249	51,291	$ 111,862	98,050
Percent change in operating profit	[1]	13.60%		14.10%
Long-lived assets		$ 32,960	35,865	$ 32,960	35,865
Percent change in long-lived assets		(8.10%)		(8.10%)
Operating Segments [Member] | Energy Systems & Controls [Member]
Segment Reporting Information [Line Items]
Net sales		$ 130,543	123,585	$ 255,590	242,349
Percent change in net sales		5.60%		5.50%
Gross profit		$ 73,720	68,410	$ 144,775	134,647
Percent change in gross profit		7.80%		7.50%
Operating profit	[1]	$ 32,867	27,769	$ 63,103	51,951
Percent change in operating profit	[1]	18.40%		21.50%
Long-lived assets		$ 9,376	11,187	$ 9,376	11,187
Percent change in long-lived assets		(16.20%)		(16.20%)
Corporate [Member]
Segment Reporting Information [Line Items]
Unallocated corporate general and administrative expenses	[1]	$ 37,731	$ 29,607	$ 72,101	$ 58,779

[1] * Segment operating profit is before unallocated corporate general and administrative expenses. These expenses were $37,731 and $29,607 for the three months ended June 30, 2017 and 2016, respectively, and $72,101 and $58,779 for the six months ended June 30, 2017 and 2016, respectively.