CONSOLIDATED STATEMENTS OF CASH FLOWS (Parentheticals) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Purchases, funding	$ 8.3	$ 8.2	$ 7.9

The cash outflow related to funding the decommissioning trust fund.

No definition available.

Name:	ee_PaymentsToFundDecommissioningFund
Namespace Prefix:	ee_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration