Summary Of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2011

Summary Of Significant Accounting Policies [Abstract]

Utility Taxes

	Three months ended September 30,				Nine months ended September 30,
	2011		2010		2011		2010
Utility taxes	$	10,270	$	9,742	$	41,551	$	37,453

Other Expense-Net

	Three months ended September 30						, Nine months ended September 30,
	2011			2010			2011			2010
Interest income	$	(455	)	$	(393	)	$	(1,029	)	$	(991	)
Interest on regulatory deferrals		(15	)		(58	)		(83	)		(188	)
Equity-related AFUDC		(421	)		(552	)		(1,655	)		(1,436	)
Net loss on investments		560			137			597			766
Other expense		1,957			1,676			5,466			5,718
Other income		—			(3	)		(235	)		(394	)
Total	$	1,626		$	807		$	3,061		$	3,475

Investments And Funds Held For Customers

	Amortized Cost		Unrealized Gain (Loss)			Fair Value
Money market funds	$	57,323	$	—		$	57,323
Securities available for sale:
U.S. government agency		34,800		17			34,817
Municipal		429		—			429
Corporate fixed income - financial		7,214		(12	)		7,202
Corporate fixed income - industrial		4,771		(21	)		4,750
Total securities available for sale		47,214		(16	)		47,198
Total investments and funds held for customers	$	104,537	$	(16	)	$	104,521

Contractual Maturities Of Securities Available For Sale

	One year or less		One year to two years		Two years to three years		Three years to four years		Four years to five years		After five years
Maturity date	$	16,034	$	2,529	$	11,486	$	4,142	$	8,022	$	4,985

Goodwill

					Accumulated Impairment
	Ecova		Other		Losses			Total
Balance as of the December 31, 2010	$	20,689	$	12,979	$	(7,733	)	$	25,935
Adjustments		177		—		—			177
Balance as of the September 30, 2011	$	20,866	$	12,979	$	(7,733	)	$	26,112

Other Intangible Amortization

	Three months ended September 30,				Nine months ended September 30,
	2011		2010		2011		2010
Other intangible amortization	$	1,145	$	933	$	3,298	$	2,840

Future Estimated Amortization Expense

	2011		2012		2013		2014		2015
Estimated amortization expense	$	1,290	$	4,709	$	3,980	$	3,077	$	1,690

Accumulated Amortization Of Other Intangibles

	September 30, 2011			December 31, 2010
Client relationships	$	11,459		$	11,459
Software development costs		21,368			19,139
Other		1,501			1,450
Total other intangibles		34,328			32,048
Client relationships accumulated amortization		(3,225	)		(2,156	)
Software development costs accumulated amortization		(11,110	)		(8,985	)
Other accumulated amortization		(910	)		(806	)
Total accumulated amortization		(15,245	)		(11,947	)
Total other intangibles - net	$	19,083		$	20,101