Goodwill, Customer Relationships and Other Intangible Assets (Details 4) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [rollforward]
Goodwill at the beginning of the period	$ 19,650	$ 20,742
Goodwill acquired during period	10,825	49
Goodwill transfered to assets-held-for sale		(1,141)
Goodwill at the end of the period	30,475	19,650
Business
Goodwill [rollforward]
Goodwill at the beginning of the period	9,372	10,464
Goodwill acquired during period	10,825	49
Goodwill at the end of the period	20,197	9,372
Goodwill accumulated impairment loss	1,100
Consumer
Goodwill [rollforward]
Goodwill at the beginning of the period	10,278	10,278
Goodwill acquired during period	0	0
Goodwill at the end of the period	$ 10,278	10,278
Colocation Business and Data Centers | Business
Goodwill [rollforward]
Goodwill transfered to assets-held-for sale		(1,141)
Colocation Business and Data Centers | Consumer
Goodwill [rollforward]
Goodwill transfered to assets-held-for sale		$ 0