Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Schedule of Segment Reporting Information By Segment [Abstract]
Net Operating Revenues	$ 3,356,514	$ 2,806,651
Operating Income (Loss)	833,074	559,772
Other Income (Expense), Net	(10,134)	10,631
Interest Expense, Net	61,921	50,269
Income Before Income Taxes	761,019	520,134
Total Assets	28,232,613		27,336,578
United States [Member]
Schedule of Segment Reporting Information By Segment [Abstract]
Net Operating Revenues	3,031,852	2,591,341
Operating Income (Loss)	690,526	530,951
Total Assets	25,249,005		24,523,072
Canada [Member]
Schedule of Segment Reporting Information By Segment [Abstract]
Net Operating Revenues	183,743	88,070
Operating Income (Loss)	71,413	(38,584)
Total Assets	1,070,239		1,202,031
Trinidad [Member]
Schedule of Segment Reporting Information By Segment [Abstract]
Net Operating Revenues	135,348	121,070
Operating Income (Loss)	80,895	77,213
Total Assets	1,065,583		1,012,727
Other International [Member]
Schedule of Segment Reporting Information By Segment [Abstract]
Net Operating Revenues	5,571	6,170
Operating Income (Loss)	(9,760)	(9,808)
Total Assets	$ 847,786		$ 598,748