Segment Information (Revenues And Long-Lived Assets By Geographic Area) (Details) (USD $) In Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Dec. 31, 2010
Segment Reporting Information [Line Items]
North America	$ 1,250,708	[1],[2]	$ 945,973	[1],[2]	$ 3,475,707	[1],[2]	$ 2,570,591	[1],[2]
Total	1,600,954	[1]	1,216,913	[1]	4,457,449	[1]	3,281,787	[1]
North America	23,283	[2],[3]			23,283	[2],[3]			12,198	[2],[3]
Property and equipment, net	664,609	[3]			664,609	[3]			570,448	[3]
United Kingdom [Member]
Segment Reporting Information [Line Items]
Revenues	183,737		153,503		522,908		390,469
Europe [Member]
Segment Reporting Information [Line Items]
Revenues	290,606	[1],[4]	229,679	[1],[4]	823,232	[1],[4]	603,481	[1],[4]
Long-lived Assets	4,773	[3]			4,773	[3]			3,687	[3]
Other Regions [Member]
Segment Reporting Information [Line Items]
Revenues	59,640	[1],[5]	41,261	[1],[5]	158,510	[1],[5]	107,715	[1],[5]
Long-lived Assets	$ 636,553	[3],[5],[6]			$ 636,553	[3],[5],[6]			$ 554,563	[3],[5],[6]

[1] Revenues are attributed to regions based upon customer location.

[2] Substantially all relates to operations in the United States.

[3] Long-lived assets include property and equipment, net of accumulated depreciation and amortization.

[4] Includes revenue from operations in the United Kingdom of $183,737 and $153,503 for the three months ended and $522,908 and $390,469 for the nine months ended September 30, 2011 and 2010, respectively.

[5] Includes our operations in Asia Pacific, Middle East and Latin America.

[6] Substantially all of these long-lived assets relate to our operations in India.