Segment and Geographic Information - Geographic Sales & PP&E (Details) - USD ($) $ in Thousands		3 Months Ended							6 Months Ended				12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017		Apr. 01, 2017	Jun. 30, 2018		Jul. 01, 2017		Dec. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		$ 7,392,528	[1]	$ 7,539,449	$ 6,856,108	$ 6,422,226	[1]	$ 5,736,780	$ 14,268,141	[1]	$ 12,159,006	[1]	$ 26,554,563
Property, plant, and equipment, net		835,801		838,475					835,801				838,475
Americas [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Property, plant, and equipment, net	[2]	687,594		688,637					687,594				688,637
EMEA [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Property, plant, and equipment, net		106,226		108,232					106,226				108,232
Asia Pacific [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Property, plant, and equipment, net		41,981		41,606					41,981				41,606
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		2,968,469				2,667,958			5,618,137		5,010,086
Property, plant, and equipment, net		683,460		$ 683,988					683,460				$ 683,988
Global ECS [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		2,108,164				1,959,876			4,053,845		3,637,853
Global ECS [Member] | Americas [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		1,387,034				1,307,245			2,582,445		2,401,888
Global ECS [Member] | EMEA [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	[3]	721,130				652,631			1,471,400		1,235,965
Global Components [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		5,284,364				4,462,350			10,214,296		8,521,153
Global Components [Member] | Americas [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		1,937,882				1,700,241			3,734,580		3,263,786
Global Components [Member] | EMEA [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	[3]	1,447,972				1,192,393			2,926,358		2,310,672
Global Components [Member] | Asia Pacific [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales		$ 1,898,510				$ 1,569,716			$ 3,553,358		$ 2,946,695

[1] Includes sales related to the United States of $2,968,469 and $5,618,137 for the second quarter and first six months of 2018 and $2,667,958 and $5,010,086 for the second quarter and first six months of 2017, respectively.

[2] Includes net property, plant, and equipment related to the United States of $683,460 and $683,988 at June 30, 2018 and December 31, 2017, respectively.

[3] Defined as Europe, the Middle East, and Africa.