Acquisitions (Details 6) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2014 USD ($) item shares	Jun. 30, 2015 USD ($) item	Mar. 31, 2015 USD ($) item
Estimated fair values of the assets acquired and liabilities assumed
Goodwill		$ 1,451,654	$ 1,402,761
Change
Goodwill		$ 1,973
Water treatment facilities and equipment | Minimum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		3 years
Water treatment facilities and equipment | Maximum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		30 years
Buildings and leasehold improvements | Minimum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		3 years
Buildings and leasehold improvements | Maximum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		40 years
Water Solutions Facilities - 2015 Acquisitions
Acquisitions
Number of water treatment disposal facilities acquired | item			16
Ownership interest acquired (as a percent)	75.00%
Number of additional water disposal facilities acquired | item	1
Cash paid to acquire ownership interests	$ 190,000
Value of common units issued	$ 37,800
Number of combined water treatment and disposal facilities acquired | item	17
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions
Acquisitions
Number of business combinations for which acquisition accounting is completed | item		12
Estimated fair values of the assets acquired and liabilities assumed
Accounts receivable - trade		$ 939	$ 939
Inventories		253	253
Prepaid expenses and other current assets		62	62
Goodwill		93,358	93,358
Other noncurrent assets		50	50
Accounts payable - trade		(58)	(58)
Accrued expenses and other payables		(1,092)	(1,092)
Other noncurrent liabilities		(420)	(420)
Noncontrolling interest		(5,775)	(5,775)
Fair value of net assets acquired		166,025	166,025
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Customer relationships
Estimated fair values of the assets acquired and liabilities assumed
Intangible assets		$ 10,000	10,000
Useful life of intangible assets		4 years
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Water treatment facilities and equipment
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 60,784	60,784
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Water treatment facilities and equipment | Minimum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		3 years
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Water treatment facilities and equipment | Maximum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		30 years
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Buildings and leasehold improvements
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 5,701	5,701
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Buildings and leasehold improvements | Minimum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		7 years
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Buildings and leasehold improvements | Maximum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		30 years
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Land
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 2,122	2,122
Water Solutions Facilities - 2015 Acquisitions, 12 completed acquisitions | Other
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 101	101
Useful life of property, plant and equipment		5 years
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion
Acquisitions
Number of business combinations for which acquisition accounting remains to be completed | item		5
Estimated fair values of the assets acquired and liabilities assumed
Goodwill		$ 39,412
Accrued expenses and other payables		(2,000)
Other noncurrent liabilities		(162)
Fair value of net assets acquired		61,736
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Estimated
Estimated fair values of the assets acquired and liabilities assumed
Goodwill			39,412
Accrued expenses and other payables			(2,000)
Other noncurrent liabilities			(162)
Fair value of net assets acquired			61,736
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Water treatment facilities and equipment
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 18,922
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Water treatment facilities and equipment | Estimated
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment			18,922
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Water treatment facilities and equipment | Minimum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		3 years
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Water treatment facilities and equipment | Maximum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		30 years
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Buildings and leasehold improvements
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 4,549
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Buildings and leasehold improvements | Estimated
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment			4,549
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Buildings and leasehold improvements | Minimum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		7 years
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Buildings and leasehold improvements | Maximum
Estimated fair values of the assets acquired and liabilities assumed
Useful life of property, plant and equipment		30 years
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Land
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 987
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Land | Estimated
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment			987
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Other
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment		$ 28
Useful life of property, plant and equipment		5 years
Water Solutions Facilities - 2015 Acquisitions, five in the process of completion | Other | Estimated
Estimated fair values of the assets acquired and liabilities assumed
Property, plant and equipment			$ 28
Common Units | Water Solutions Facilities - 2015 Acquisitions
Acquisitions
Common units issued | shares	1,322,032