Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 2,470,047	[1]	$ 2,392,220	[2]	$ 2,368,832	[2]
Gain (Loss) on Investments	(14,231)		0		(992)
Amortization of stock-based compensation	39,122		39,825		47,274
Shipping, Handling and Transportation Costs	90,709		79,257		77,399
Global Components [Member]
Goodwill [Line Items]
Goodwill	1,264,869	[1]	1,239,741	[2]	1,230,832	[2]
Global ECS [Member]
Goodwill [Line Items]
Goodwill	1,205,178	[1]	$ 1,152,479	[2]	$ 1,138,000	[2]
Americas [Member] | Global Components [Member]
Goodwill [Line Items]
Goodwill	1,115,938
Americas [Member] | Global ECS [Member]
Goodwill [Line Items]
Goodwill	795,755
EMEA [Member] | Global Components [Member]
Goodwill [Line Items]
Goodwill	87,692
EMEA [Member] | Global ECS [Member]
Goodwill [Line Items]
Goodwill	409,423
Asia/Pacific [Member] | Global Components [Member]
Goodwill [Line Items]
Goodwill	$ 61,239

[1] The total carrying value of goodwill of companies acquired as of December 31, 2017 in the table above is reflected net of $1,026,702 of accumulated impairment charges, of which $716,925 was recorded in the global components business segment and $309,777 was recorded in the global ECS business segment.

[2] The total carrying value of goodwill of companies acquired as of December 31, 2016 and December 31, 2015 in the table above is reflected net of $1,018,780 of accumulated impairment charges, of which $716,925 was recorded in the global components business segment and $301,855 was recorded in the global ECS business segment.