Nuclear Decommissioning Trust Fund

9 Months Ended

Sep. 30, 2019

Nuclear Decommissioning Trust Fund Disclosure [Abstract]

NRG's Nuclear Decommissioning Trust Fund assets, which are for the decommissioning of its 44% interest in STP, are comprised of securities classified as available-for-sale and recorded at fair value based on actively quoted market prices. NRG accounts for the Nuclear Decommissioning Trust Fund in accordance with ASC 980, Regulated Operations, because the Company's nuclear decommissioning activities are subject to approval by the PUCT with regulated rates that are designed to recover all decommissioning costs and that can be charged to and collected from the ratepayers per PUCT mandate. Since the Company is in compliance with PUCT rules and regulations regarding decommissioning trusts and the cost of decommissioning is the responsibility of the Texas ratepayers, not NRG, all realized and unrealized gains or losses (including other-than-temporary impairments) related to the Nuclear Decommissioning Trust Fund are recorded to the Nuclear Decommissioning Trust liability and are not included in net income or accumulated OCI, consistent with regulatory treatment.

The following table summarizes the aggregate fair values and unrealized gains and losses for the securities held in the trust funds, as well as information about the contractual maturities of those securities.


	As of September 30, 2019													As of December 31, 2018
(In millions, except maturities)	Fair Value		Unrealized Gains		Unrealized Losses		Weighted-average Maturities (In years)	Fair Value		Unrealized Gains		Unrealized Losses		Weighted-average Maturities (In years)
Cash and cash equivalents	$	20	$	—	$	—	—	$	19	$	—	$	—	—
U.S. government and federal agency obligations	51		5		—		13	46		1		—		12
Federal agency mortgage-backed securities	97		3		—		24	100		1		2		23
Commercial mortgage-backed securities	27		1		1		24	22		—		1		22
Corporate debt securities	112		6		—		11	96		1		2		11
Equity securities	444		295		—		—	376		231		1		—
Foreign government fixed income securities	5		—		—		10	4		—		—		9
Total	$	756	$	310	$	1		$	663	$	234	$	6

The following table summarizes proceeds from sales of available-for-sale securities held in the trust funds and the related realized gains and losses from these sales. The cost of securities sold is determined on the specific identification method.


	Nine months ended September 30,
	2019		2018
	(In millions)
Realized gains	$	8	$	8
Realized losses	(7)		(8)
Proceeds from sale of securities	271		398