ARO Trust (Notes)

12 Months Ended

Dec. 31, 2014

Investments, Debt and Equity Securities [Abstract]

ARO Trust

ARO TRUST

Available-for-Sale Investments

We are entitled to collect in rates the amounts necessary to fund our asset retirement obligations (ARO). We deposit monthly, into an external trust account, the revenues specifically designated for ARO. We established the ARO trust account (ARO Trust) on June 30, 2008. The ARO Trust carries a moderate risk portfolio. We measure the financial instruments held in our ARO Trust at fair value. However, in accordance with the ASC Topic 980, Regulated Operations, both realized and unrealized gains and losses of the ARO Trust are recorded as regulatory assets or liabilities.

Effective March 1, 2013, the annual funding obligation is approximately $36.4 million, with deposits made monthly.

Investments in available-for-sale securities within the ARO Trust at fair value were as follows (in millions):

	December 31, 2014				December 31, 2013
	Amortized Cost Basis		Fair Value		Amortized Cost Basis		Fair Value
Cash and Money Market Funds	$	2.1	$	2.1	$	6.5	$	6.5
U.S. Equity Funds	15.0		19.0		8.0		11.1
International Equity Funds	8.0		8.2		4.2		4.9
Municipal Bond Funds	17.7		18.2		10.2		10.2
Total	$	42.8	$	47.5	$	28.9	$	32.7