Segment Information (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 60,514,818	$ 53,097,879
US Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	18,603,423	18,140,825
US Non-Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	15,959,206	13,712,106
Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	34,562,629	31,852,931
Canada Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,161,452	3,846,682
Canada Non-Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	126,372	85,405
Canada Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,287,824	3,932,087
EMEA Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	3,099,495	2,559,124
EMEA Non-Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	5,274,993	3,876,131
EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	8,374,488	6,435,255
Asia Pacific Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,915,442	3,968,081
Asia Pacific Non-Traditional Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,198,585	676,281
Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	6,114,027	4,644,362
Corporate Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 7,175,850	$ 6,233,244