Acquisitions - Additional Information (Details) (USD $)
In Thousands, unless otherwise specified
6 Months Ended
Jun. 30, 2014
Dec. 31, 2013
Jun. 30, 2014
Regulated Water and Wastewater Systems
Investment
Business Acquisition [Line Items]      
Business acquisition, number of companies acquired     5
Purchase price     $ 2,869
Purchase price allocation, assets acquired, plant     5,985
Purchase price allocation, liabilities assumed     3,117
Contributions in aid of construction 1,054,328 1,042,704 1,425
Debt related to purchase price allocation $ 1,683   $ 1,683