Unconsolidated Investees (Details 6) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Other unconsolidated investees, investment in and advances to entities
Investments in and advances to unconsolidated investees	$ 2,857,755	$ 2,024,661
Other Unconsolidated Investees [Member]
Other unconsolidated investees, investment in and advances to entities
Investments in and advances to unconsolidated investees	386,576	134,645
Other Unconsolidated Investees [Member] | Americas [Member]
Other unconsolidated investees, investment in and advances to entities
Estimated total investment to complete existing development	305,352	17,508
Other Unconsolidated Investees [Member] | Europe [Member]
Other unconsolidated investees, investment in and advances to entities
Estimated total investment to complete existing development	50,474	49,857
Other Unconsolidated Investees [Member] | Asia [Member]
Other unconsolidated investees, investment in and advances to entities
Estimated total investment to complete existing development	$ 30,750	$ 67,280