Nature of Operations and Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization And Summary Of Significant Accounting Policies [Line Items]
Advertising and promotional expenses		$ 5,400	$ 6,800	$ 6,400
Allowance for credit losses on accounts receivable		789	275
Impairment of goodwill		$ 0	$ 0	$ 0
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives		1 year
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives		12 years
Building | Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		7 years
Building | Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		25 years
Information technology assets | Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		3 years
Information technology assets | Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		5 years
Server Equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		3 years
Server Equipment | Subsequent Event
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to	4 years
Network Equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		3 years
Network Equipment | Subsequent Event
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to	5 years
Network Equipment | Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		3 years
Network Equipment | Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful lives, up to		5 years
Geographic Area | Revenue
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue		100.00%	100.00%	100.00%
Geographic Area | Revenue | United States
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue		47.00%	46.00%	46.00%