Segment Information Major Customers (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012
Revenue, Major Customer [Line Items]
Segment Reporting, Disclosure of Major Customers	For the years ended December 31, 2014 and 2013, no single customer represented more than 10% of total Company or the Electricity, Gas or Water operating segment revenues. For the year ended December 31, 2012, no single customer represented more than 10% of total Company or the Gas or Water operating segment revenues
Sales [Member] | Threshold for Reporting Customer Concentration [Member]
Revenue, Major Customer [Line Items]
Percentage of total company revenue represented by one customer	10.00%
Sales [Member] | Customer A [Member] | Electricity Operating Segment [Member]
Revenue, Major Customer [Line Items]
Percentage of total company revenue represented by one customer		17.00%