Short-Term Borrowings (Tables)

12 Months Ended

Dec. 31, 2011

Schedule Of Borrowings Outstanding And Letters Of Credit

	2011			2010			2009
Balance outstanding at end of period	$	61,000		$	110,000		$	87,000
Letters of credit outstanding at end of period	$	29,030		$	27,126		$	28,448
Average interest rate at end of period		1.12	%		0.57	%		0.59	%

Ecova [Member]

Schedule Of Borrowings Outstanding And Letters Of Credit

	2011			2010		2009
Balance outstanding at end of period	$	35,000		$	—	$	5,700
Average interest rate at end of period		2.38	%		—		1.23	%