Geographic Operating Segment Information (Reconciliation Of Assets From Segment To Consolidated) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Total consolidated assets	$ 10,353,088	$ 9,679,102
United States [Member]
Total consolidated assets	10,222,200	8,987,141
South Africa [Member]
Total consolidated assets	85,017	134,901
Tunisia [Member]
Total consolidated assets		325,942
Headquarters [Member]
Total consolidated assets	$ 45,871	$ 231,118