Segment Information (Total Revenues of Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 2,716,588	$ 2,389,815	$ 8,206,781	$ 7,581,559
US Traditional Segment Reporting Information [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,310,879	1,258,278	3,922,598	3,730,533
US Non-Traditional Segment Reporting Information [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	261,128	91,501	843,197	707,592
Canada Segment Reporting Information [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	297,340	292,504	884,202	884,918
EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	392,912	329,851	1,150,087	947,607
Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	428,432	393,657	1,326,632	1,187,486
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 25,897	$ 24,024	$ 80,065	$ 123,423