Segment Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financial information with respect to entity's operations by geographic area
Operating revenues and Earnings (losses) from unconsolidated affiliates from continuing operations:	$ 1,605,390	$ 1,548,965	$ 1,459,326	$ 1,538,373	$ 1,571,745	$ 1,630,380	$ 1,541,841	$ 1,810,367	$ 6,152,054	$ 6,554,333	$ 6,098,928
Property, plant and equipment, net	8,597,813				8,712,088				8,597,813	8,712,088	8,629,946
Goodwill	512,964				472,326				512,964	472,326	501,258
U.S.
Financial information with respect to entity's operations by geographic area
Operating revenues and Earnings (losses) from unconsolidated affiliates from continuing operations:									4,146,125	4,625,614	4,311,009
Property, plant and equipment, net	5,474,746				5,179,578				5,474,746	5,179,578	4,974,239
Goodwill	498,149				456,463				498,149	456,463	57,445
Outside the U.S.
Financial information with respect to entity's operations by geographic area
Operating revenues and Earnings (losses) from unconsolidated affiliates from continuing operations:									2,005,929	1,928,719	1,787,919
Property, plant and equipment, net	3,123,067				3,532,510				3,123,067	3,532,510	3,655,707
Goodwill	$ 14,815				$ 15,863				$ 14,815	$ 15,863	$ 34,464