Dispositions (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended	1 Months Ended			1 Months Ended			1 Months Ended
	Jun. 30, 2011	Dec. 31, 2008	Jul. 31, 2011 Maine [Member]	Sep. 30, 2011 Maine [Member]	Jun. 30, 2011 Maine [Member]	Jul. 31, 2011 New York [Member]	Sep. 30, 2011 New York [Member]	Jun. 30, 2011 New York [Member]	May 31, 2011 Missouri [Member]	Mar. 31, 2011 Texas [Member]	Jun. 30, 2011 Texas [Member]
Proceeds from sale of regulated water operations	$ 4,106		$ 35,800			$ 42,000			$ 3,225	$ 3,118
Liabilities assumed from sale of regulated water operations			17,500			23,000
Carrying amount of assets					57,340			105,801
Carrying amount of liabilities					39,501			63,905
Number of customers					16,000			51,000			5,300
Deferred tax liabilities				5,000			2,500
Gain on sale of water and wastewater utility system	1,580									2,452
Initial valuation payment		$ 16,911
Percentage of utility system that has been relinquished		0.40%