Investment In Unconsolidated Affiliates Carrying Value of Unconsolidated Affiliates (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investment in unconsolidated affiliates, carrying value	$ 2,102,503	$ 1,924,705
HPC [Member]
Investment in unconsolidated affiliates, carrying value	673,510	682,046
MEP [Member]
Investment in unconsolidated affiliates, carrying value	596,696	613,942
Lone Star [Member]
Investment in unconsolidated affiliates, carrying value	809,958	628,717
Ranch JV [Member]
Investment in unconsolidated affiliates, carrying value	$ 22,339	$ 0