Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Nov. 28, 2011	Nov. 22, 2011	Aug. 31, 2007 Rate	Aug. 15, 2007 Rate
Commitments And Contingencies [Line Items]
Expiration year of lease	2017
Rental expenses under operating leases	$ 3,000,000	$ 10,600,000	$ 15,300,000
Number of domain names registered	106,200,000
Uncertain tax positions	46,400,000
Line of Credit Facility, Current Borrowing Capacity					200,000,000
Line of Credit Facility, Amount Outstanding				100,000,000
Principal amount of convertible debentures	1,250,000,000	1,250,000,000					1,250,000,000
Convertible debenture, interest rate						3.25%	3.25%
Limit of Tax Deductible Compensation	1,000,000
Indemnification period (months)	60
Claims threshold amount to trigger indemnification obligation	4,000,000
Percentage of claims to be indemnified	50.00%
Maximum indemnification obligation	50,000,000
ICANN Agreement [Member]
Commitments And Contingencies [Line Items]
Expiration Date of Registry Agreement	November 30, 2018
Registry fee per transaction	0.25
Payments for registry fees	18,700,000	18,000,000	18,000,000
.TV Agreement [Member]
Commitments And Contingencies [Line Items]
Expiration Date of Registry Agreement	November 22, 2016
Payments for registry fees	2,000,000
renewed agreement fees	$ 4,000,000