Commitments and Contingencies (Details)		1 Months Ended	3 Months Ended		12 Months Ended
	Nov. 10, 2009 defendant	Feb. 28, 2015 participant	Mar. 31, 2016 USD ($) a aft facility	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) aft
Loss Contingencies [Line Items]
Future minimum payments due			$ 8,240,000
Payments on water contracts			$ 6,432,000
Contract renewal optional term			35 years
Long-term water assets (volume) | aft			51,880		49,018
Estimated future payments			$ 800,000
Number of community facility districts | facility			2
Letter of credit period			2 years
Letter of credit renewal period			2 years
Reimbursement proceeds from Communities Facilities District			$ 4,162,000	$ 4,971,000
Special taxes paid					$ 963,000
Number of affiliates | defendant	2
Antelope Valley Groundwater Cases | Settled Litigation
Loss Contingencies [Line Items]
Number of parties representing majority of water use | participant		140
Percentage of water use		99.00%
KWBA | TCWD
Loss Contingencies [Line Items]
Percentage of interest rate held			2.00%
Standby letter of credit
Loss Contingencies [Line Items]
Letters of credit outstanding amount			$ 5,426,000
Annual cost related to letter of credit			$ 83,000
West CFD
Loss Contingencies [Line Items]
Acres of land related to land liens | a			420
Bond debt sold by TRPFFA			$ 28,620,000
Additional bond debt authorized to be sold in future			0
Additional reimbursement funds			$ 0
East CFD
Loss Contingencies [Line Items]
Acres of land related to land liens | a			1,931
Letters of credit outstanding amount			$ 55,000,000
Additional bond debt authorized to be sold in future			65,000,000
Additional reimbursement funds			$ 13,923,000
Transferable water | DMB
Loss Contingencies [Line Items]
Long-term water assets (volume) | aft			6,693