Contingencies and Regulatory Matters (Tables)

3 Months Ended

Mar. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Recovery Balance of Each Regulatory Clause

The balance of each regulatory clause recovery on the balance sheet follows:

Regulatory Clause	Balance Sheet Line Item	March 31, 2016		December 31, 2015
		(in millions)
Rate CNP Compliance	Under recovered regulatory clause revenues, current	$	22	$	43
Rate CNP PPA	Deferred under recovered regulatory clause revenues	105		99
Retail Energy Cost Recovery	Other regulatory liabilities, current	173		238
	Deferred over recovered regulatory clause revenues	64		—
Natural Disaster Reserve	Other regulatory liabilities, deferred	74		75

The balance of each regulatory clause recovery on the balance sheet follows:

Regulatory Clause	Balance Sheet Location	March 31, 2016		December 31, 2015
		(in millions)
Fuel Cost Recovery	Other regulatory liabilities, current	$	20	$	18
Purchased Power Capacity Recovery	Under recovered regulatory clause revenues	4		1
Environmental Cost Recovery	Under recovered regulatory clause revenues	17		19
Energy Conservation Cost Recovery	Other regulatory liabilities, current	2		4

Current And Actual Cost Estimate for Kemper IGCC

Mississippi Power's Kemper IGCC 2010 project estimate, current cost estimate (which includes the impacts of the Mississippi Supreme Court's (Court) decision discussed herein under "Rate Recovery of Kemper IGCC Costs – 2013 MPSC Rate Order"), and actual costs incurred as of March 31, 2016, are as follows:

Cost Category	2010 Project Estimate(f)		Current Cost Estimate(a)			Actual Costs
	(in billions)
Plant Subject to Cost Cap(b)(g)	$	2.40	$	5.35		$	4.99
Lignite Mine and Equipment	0.21		0.23			0.23
CO2 Pipeline Facilities	0.14		0.11			0.12
AFUDC(c)	0.17		0.71			0.62
Combined Cycle and Related Assets Placed in Service – Incremental(d)(g)	—		0.02			0.01
General Exceptions	0.05		0.10			0.09
Deferred Costs(e)(g)	—		0.20			0.18
Additional DOE Grants(h)	—		(0.14		)	—
Total Kemper IGCC	$	2.97	$	6.58		$	6.24

(a) Amounts in the Current Cost Estimate reflect estimated costs through September 30, 2016.

(b) The 2012 MPSC CPCN Order approved a construction cost cap of up to $2.88 billion, net of the Initial DOE Grants and excluding the Cost Cap Exceptions. The Current Cost Estimate and the Actual Costs include non-incremental operating and maintenance costs related to the combined cycle and associated common facilities placed in service in August 2014 that are subject to the $2.88 billion cost cap and exclude post-in-service costs for the lignite mine. See "Rate Recovery of Kemper IGCC Costs – 2013 MPSC Rate Order" herein for additional information. The Current Cost Estimate and the Actual Costs reflect 100% of the costs of the Kemper IGCC. See note (g) for additional information.

(c) Mississippi Power's original estimate included recovery of financing costs during construction rather than the accrual of AFUDC. This approach was not approved by the Mississippi PSC in 2012 as described in "Rate Recovery of Kemper IGCC Costs." The current estimate reflects the impact of a settlement agreement with the wholesale customers for cost-based rates under FERC's jurisdiction. See "FERC Matters" herein for additional information.

(d) Incremental operating and maintenance costs related to the combined cycle and associated common facilities placed in service in August 2014, net of costs related to energy sales. See "Rate Recovery of Kemper IGCC Costs – 2013 MPSC Rate Order" herein for additional information.

(e) The 2012 MPSC CPCN Order approved deferral of non-capital Kemper IGCC-related costs during construction as described in "Rate Recovery of Kemper IGCC Costs – Regulatory Assets and Liabilities" herein.

(f) The 2010 Project Estimate is the certificated cost estimate adjusted to include the certificatedestimate for the CO₂ pipeline facilities approved in 2011 by the Mississippi PSC.

(g) Beginning in the third quarter 2015, certain costs, including debt carrying costs (associated with assets placed in service and other non-CWIP accounts), that previously were deferred as regulatory assets are now being recognized through income; however, such costs continue to be included in the Current Cost Estimate and the Actual Costs at March 31, 2016.

(h) On April 8, 2016, Mississippi Power received approximately $137 million in additional grants from the DOE for the Kemper IGCC, which are expected to be used to reduce future rate impacts for customers.