Investment In Unconsolidated Affiliates Carrying Value of Unconsolidated Affiliates (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Investment in unconsolidated affiliates, carrying value	$ 2,007,414	$ 1,924,705
HPC [Member]
Investment in unconsolidated affiliates, carrying value	675,734	682,046
MEP [Member]
Investment in unconsolidated affiliates, carrying value	605,303	613,942
Lone Star [Member]
Investment in unconsolidated affiliates, carrying value	712,965	628,717
Ranch JV [Member]
Investment in unconsolidated affiliates, carrying value	$ 13,412	$ 0