Revenue (Disaggregation of revenue) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,268,095	$ 2,566,465	$ 2,454,479
Industrials Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	453,576	493,063	496,436
Aerospace And Defense Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	431,923	406,402	391,690
Medical Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	448,202	393,967	373,785
Semi-Cap Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	277,765	354,978	346,341
Computing Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	361,213	580,845	540,360
Telecommunications Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	295,416	337,210	305,867
Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,346,809	2,635,231	2,539,299
Elimination Of Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	78,714	68,766	84,820
Americas [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,383,848	1,617,530	1,554,250
Americas [Member] | Industrials Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	165,163	184,500	213,699
Americas [Member] | Aerospace And Defense Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	400,326	374,852	361,200
Americas [Member] | Medical Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	263,688	235,287	204,677
Americas [Member] | Semi-Cap Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	102,908	155,687	158,151
Americas [Member] | Computing Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	308,077	504,391	444,401
Americas [Member] | Telecommunications Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	143,686	162,813	172,122
Americas [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,428,795	1,647,402	1,584,729
Americas [Member] | Elimination Of Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	44,947	29,872	30,479
Asia [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	708,576	762,769	723,493
Asia [Member] | Industrials Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	214,575	241,765	213,504
Asia [Member] | Aerospace And Defense Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	2,430
Asia [Member] | Medical Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	167,296	144,528	149,650
Asia [Member] | Semi-Cap Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	123,764	135,299	140,967
Asia [Member] | Computing Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	53,051	69,657	85,988
Asia [Member] | Telecommunications Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	149,890	171,520	130,954
Asia [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	741,630	801,312	777,616
Asia [Member] | Elimination Of Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	33,054	38,543	54,123
Europe [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	175,671	186,166	176,736
Europe [Member] | Industrials Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	73,838	66,798	69,233
Europe [Member] | Aerospace And Defense Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	31,597	31,550	28,060
Europe [Member] | Medical Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	17,218	14,152	19,458
Europe [Member] | Semi-Cap Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	51,093	63,992	47,223
Europe [Member] | Computing Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	85	6,797	9,971
Europe [Member] | Telecommunications Sector [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,840	2,877	2,791
Europe [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	176,384	186,517	176,954
Europe [Member] | Elimination Of Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 713	$ 351	$ 218