Segment Information (Total Assets of Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Segment Total Assets [Line Items]
Total assets	$ 39,526,555	$ 40,360,438
US Segment Reporting Information [Member]
Segment Total Assets [Line Items]
Total assets	24,601,693	24,924,363
Canada Segment Reporting Information [Member]
Segment Total Assets [Line Items]
Total assets	4,065,475	3,764,002
Europe And South Africa Segment Reporting Information [Member]
Segment Total Assets [Line Items]
Total assets	2,403,094	2,235,199
Asia Pacific Segment Reporting Information [Member]
Segment Total Assets [Line Items]
Total assets	3,396,639	3,208,732
Corporate And Other Segment Reporting Information [Member]
Segment Total Assets [Line Items]
Total assets	$ 5,059,654	$ 6,228,142