Regulation (Refund Fuel Cost Over Recoveries) (Details) (USD $) In Thousands, unless otherwise specified	May 12, 2010 PUCT Docket No. 38253	Oct. 20, 2010 PUCT Docket No. 38802	Feb. 18, 2011 PUCT Docket No. 39159	Aug. 03, 2012 Puct Docket No. 40622
Refund Amount Authorized	$ 11,100	$ 12,800	$ 11,800	$ 6,600