Other Information (Other Non-Current Assets) (Details) (USD $) In Thousands, unless otherwise specified			9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Financing Costs (3 to 30 years) [Member] years
Unamortized financing costs (3 to 30 years)	$ 41,370	$ 35,267
Regulatory assets	89,943	92,939
Other	24,172	30,400
Total non-current other assets, net	$ 155,485	$ 158,606
Financing cost, amortization period, minimum (years)			3
Financing cost, amortization period, maximum (years)			30