Commitments And Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments And Contingencies [Line Items]

Schedule Of Rent Expense Under Operating Leases

		Years Ended December 31,
		2012		2011		2010
Operating lease expense	$	3,850	$	3,553	$	3,631
Purchased water under
long-term agreements		11,796		14,507		13,621
Water treatment expense
under contractual agreement		897		865		777

Motor Vehicles, Buildings And Other Equipment [Member]

Commitments And Contingencies [Line Items]

Schedule Of Future Annual Minimum Lease Payments

	2013		2014		2015		2016		2017		Thereafter
$	2,568	$	1,925	$	1,191	$	483	$	$ 131	$	476

Treatment Plants [Member]

Commitments And Contingencies [Line Items]

Schedule Of Future Annual Minimum Lease Payments

	2013		2014		2015		2016		2017		Thereafter
$	494	$	494	$	496	$	507	$	507	$	3,466