Goodwill, Customer Relationships and Other Intangible Assets - Rollforward of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Goodwill [Roll Forward]
As of December 31, 2018	$ 28,031,000
January 2019 reorganization	0
Effect of foreign currency rate change	1,000
Impairment of goodwill	(6,506,000)	$ 0
As of March 31, 2019	21,526,000
International and Global Accounts
Goodwill [Roll Forward]
As of December 31, 2018	3,595,000
January 2019 reorganization	0
Effect of foreign currency rate change	1,000
Impairment of goodwill	(934,000)
As of March 31, 2019	2,662,000
Enterprise
Goodwill [Roll Forward]
As of December 31, 2018	5,222,000
January 2019 reorganization	987,000
Effect of foreign currency rate change	0
Impairment of goodwill	(1,471,000)
As of March 31, 2019	4,738,000
Small and Medium Business
Goodwill [Roll Forward]
As of December 31, 2018	5,193,000
January 2019 reorganization	(1,038,000)
Effect of foreign currency rate change	0
Impairment of goodwill	(896,000)
As of March 31, 2019	3,259,000
Wholesale
Goodwill [Roll Forward]
As of December 31, 2018	6,437,000
January 2019 reorganization	395,000
Effect of foreign currency rate change	0
Impairment of goodwill	(3,019,000)
As of March 31, 2019	3,813,000
Consumer
Goodwill [Roll Forward]
As of December 31, 2018	7,584,000
January 2019 reorganization	(344,000)
Effect of foreign currency rate change	0
Impairment of goodwill	(186,000)
As of March 31, 2019	$ 7,054,000