Segment Information (Revenues By Geographic Location) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 739,996	$ 619,366	$ 641,422	$ 615,210	$ 589,495	$ 565,348	$ 530,790	$ 490,888	$ 2,586,123	$ 2,206,392	$ 1,874,662
Enterprise Divisions [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									2,074,800	1,778,646	1,514,045
Enterprise Divisions [Member] | Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									1,106,801	993,062	837,689
Enterprise Divisions [Member] | EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									691,111	576,953	519,828
Enterprise Divisions [Member] | Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									276,888	208,631	156,528
Online Services division revenues
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									511,323	427,746	360,617
Online Services division revenues | Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									433,263	367,260	330,493
Online Services division revenues | EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									63,484	50,711	23,258
Online Services division revenues | Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									$ 14,576	$ 9,775	$ 6,866