Goodwill (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Goodwill [Line Items]
Balance	$ 31,184
Goodwill acquired	12
Reclassifications (to) from utility plant acquisition adjustment, net	2,758
Balance	33,954
Regulated Segments [Member]
Goodwill [Line Items]
Balance	24,564
Reclassifications (to) from utility plant acquisition adjustment, net	2,758
Balance	27,322
Corporate and Other [Member]
Goodwill [Line Items]
Balance	6,620
Goodwill acquired	12
Reclassifications (to) from utility plant acquisition adjustment, net
Balance	$ 6,632