SOUTHERN Co GAS (GAS) 10-Q/A 26 Nov 14 2014 Q1 Quarterly report (amended) Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 22, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'AGL RESOURCES INC	'
Document Type	'10-Q	'
Current Fiscal Year End Date	'--12-31	'
Entity Common Stock, Shares Outstanding	'	119,257,873
Amendment Flag	'true	'
Amendment Description	'Amendment	'
Entity Central Index Key	'0001004155	'
Entity Current Reporting Status	'Yes	'
Entity Voluntary Filers	'No	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Well-known Seasoned Issuer	'Yes	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Financial Position (Unaudited) (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
In Millions, unless otherwise specified
Current assets	'		'		'
Cash and cash equivalents	$267		$81		$122
Short-term investments	49		49		41
Receivables	'		'		'
Energy marketing	1,226		786		627
Gas, unbilled and other	1,075		736		839
Less allowance for uncollectible accounts	49		29		39
Total receivables, net	2,252		1,493		1,427
Inventories, net	253		658		384
Assets held for sale	264		283		291
Regulatory assets	250	[1]	114	[1]	72	[1]
Derivative instruments	127		99		100
Other	127		118		93
Total current assets	3,589	[1],[2]	2,895	[1],[2]	2,530	[1],[2]
Long-term assets and other deferred debits	'		'		'
Property, plant and equipment	11,054		10,938		10,450
Less accumulated depreciation	2,367		2,295		2,181
Property, plant and equipment, net	8,687		8,643		8,269
Goodwill	1,827	[3]	1,827	[3]	1,822	[3]
Regulatory assets	696	[1]	705	[1]	868	[1]
Intangible assets	140		145		131
Derivative instruments	11		20		11
Other	314		315		231
Total long-term assets and other deferred debits	11,675		11,655		11,332
Total assets	15,264	[1],[2]	14,550	[1],[2]	13,862	[1],[2]
Current liabilities	'		'		'
Energy marketing trade payables	1,119		671		653
Short-term debt	741		1,171		868
Other accounts payable - trade	434		421		306
Accrued expenses	385		203		161
Temporary LIFO liquidation	252		'		179
Current portion of long-term debt and capital leases	200		'		226
Regulatory liabilities	161	[1]	183	[1]	238	[1]
Customer deposits and credit balances	104		136		115
Accrued environmental remediation liabilities	82		70		63
Derivative instruments	63		75		20
Liabilities held for sale	36		40		34
Other	177		148		196
Total current liabilities	3,754	[1],[2]	3,118	[1],[2]	3,059	[1],[2]
Long-term liabilities and other deferred credits	'		'		'
Long-term debt	3,610		3,813		3,324
Accumulated deferred income taxes	1,655		1,628		1,539
Regulatory liabilities	1,550	[1]	1,518	[1]	1,498	[1]
Accrued pension and retiree welfare benefits	405		404		509
Accrued environmental remediation liabilities	358		377		362
Derivative instruments	19		5		4
Other	70		74		74
Total long-term liabilities and other deferred credits	7,667	[1],[2]	7,819	[1],[2]	7,310	[1],[2]
Total liabilities and other deferred credits	11,421	[1],[2]	10,937	[1],[2]	10,369	[1],[2]
Equity	'		'		'
Common stock, $5 par value; 750,000,000 shares authorized: outstanding: 119,247,421 shares at March 31, 2014, 118,888,876 shares at December 31, 2013 and 118,123,770 shares at March 31, 2013	597		595		592
Additional paid-in capital	2,060		2,054		2,020
Retained earnings	1,289		1,063		1,085
Accumulated other comprehensive loss	-135	[4]	-136	[4]	-211	[4]
Treasury shares, at cost: 216,523 shares at March 31, 2014 and December 31, 2013 and March 31, 2013	-8		-8		-8
Total common shareholders’ equity	3,803		3,568		3,478
Noncontrolling interest	40		45		15
Total equity	3,843	[1],[2]	3,613	[1],[2]	3,493	[1],[2]
Total liabilities and equity	$15,264	[1],[2]	$14,550	[1],[2]	$13,862	[1],[2]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
[3]	Excludes goodwill at Tropical Shipping which is classified as held for sale. See Note 12 for additional information.
[4]	All amounts are net of income taxes. Amounts in parentheses indicate debits to accumulated other comprehensive loss.

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Financial Position (Unaudited) (Parentheticals) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Common stock, par value (in Dollars per share)	$5	$5	$5
Common stock, shares authorized	750,000,000	750,000,000	750,000,000
Common stock, shares outstanding	119,247,421	118,888,876	118,123,770
Treasury shares, shares	216,523	216,523	216,523

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Operating revenues (includes revenue taxes of $68 for the three months in 2014 and $50 for the three months in 2013)	$2,462	[1]	$1,612	[1]
Operating expenses	'		'
Cost of goods sold	1,400	[1]	920	[1]
Operation and maintenance	289	[1]	231	[1]
Depreciation and amortization	93	[1]	102	[1]
Taxes other than income taxes	88	[1]	69	[1]
Total operating expenses	1,870	[1]	1,322	[1]
Operating income	592	[1]	290	[1]
Other income	3	[1]	5	[1]
Interest expense, net	-46		-45
Income before income taxes	549		250
Income tax expense	203		91
Income from continuing operations	346		159
(Loss) income from discontinued operations	-50	[2],[3]	1	[2],[3]
Net income	296		160
Less net income attributable to the noncontrolling interest	12		10
Net income attributable to AGL Resources Inc.	$284	[2]	$150	[2]
Basic earnings (loss) per common share	'		'
Continuing operations (in Dollars per share)	$2.82	[2],[4]	$1.27	[2],[4]
Discontinued operations (in Dollars per share)	($0.43)	[2],[4]	$0.01	[2],[4]
Basic earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$2.39	[2]	$1.28	[2]
Diluted earnings (loss) per common share	'		'
Continuing operations (in Dollars per share)	$2.81	[2],[4]	$1.26	[2],[4]
Discontinued operations (in Dollars per share)	($0.43)	[2],[4]	$0.01	[2],[4]
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$2.38	[2]	$1.27	[2]
Cash dividends declared per common share (in Dollars per share)	$0.49		$0.47
Weighted average number of common shares outstanding	'		'
Basic (in Shares)	118.5	[2],[5]	117.4	[2],[5]
Diluted (in Shares)	118.9	[2]	117.7	[2]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
[3]	For additional information on our discontinued operations, see Note 12.
[4]	Excludes net income attributable to the noncontrolling interest.
[5]	Daily weighted average shares outstanding.

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Income (Unaudited) (Parentheticals) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating revenues, revenue taxes	$68	$50

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Other Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Net income	$296		$160
Retirement benefit plans	'		'
Reclassification of actuarial losses to net benefit cost (net of income tax of $1 for the three months ended March 31, 2014, and $2 for the three months ended March 31, 2013)	1		4
Reclassification of prior service credits to net benefit cost	'		-1
Retirement benefit plans	1		3
Cash flow hedges, net of tax	'		'
Net derivative instrument gains arising during the period (net of income tax of $1 for the three months ended March 31, 2013)	4	[1]	2	[1]
Reclassification of realized derivative (gains) losses to net income (net of income tax of $1 for the three months ended March 31, 2013)	-4	[1]	2	[1]
Cash flow hedges, net	'		4
Other comprehensive income, net of tax	1		7
Comprehensive income	297		167
Less comprehensive income attributable to noncontrolling interest	12		10
Comprehensive income attributable to AGL Resources Inc.	$285		$157
[1]	All amounts are net of income taxes. Amounts in parentheses indicate debits to accumulated other comprehensive loss.

Condensed_Consolidated_Stateme5

Condensed Consolidated Statements of Other Comprehensive Income (Unaudited) (Parentheticals) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Reclassification of losses to net benefit cost, income tax	$1	$2
Net derivative instrument gains (losses) arising during the period, income tax	'	1
Reclassification of realized derivative losses to net income, income tax	'	$1

Condensed_Consolidated_Stateme6

Condensed Consolidated Statements of Equity (Unaudited) (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Total
In Millions, except Share data
Balance at Dec. 31, 2012	$590	$2,015	$990	($218)	($8)	$22	$3,391
Balance (in Shares) at Dec. 31, 2012	117,900,000	'	'	'	'	'	'
Net income	'	'	150	'	'	10	160
Other comprehensive income	'	'	'	7	'	'	7
Dividends on common stock	'	'	-55	'	'	'	-55
Distributions to noncontrolling interest	'	'	'	'	'	-17	-17
Stock granted, share-based compensation, net of forfeitures	'	-6	'	'	'	'	-6
Stock issued, dividend reinvestment plan	1	2	'	'	'	'	3
Stock issued, share-based compensation, net of forfeitures	1	6	'	'	'	'	7
Stock issued, share-based compensation, net of forfeitures (in Shares)	200,000	'	'	'	'	'	'
Stock-based compensation expense, net of tax	'	3	'	'	'	'	3
Balance at Mar. 31, 2013	592	2,020	1,085	-211	-8	15	3,493	[1],[2]
Balance (in Shares) at Mar. 31, 2013	118,100,000	'	'	'	'	'	118,123,770
Balance at Dec. 31, 2013	595	2,054	1,063	-136	-8	45	3,613	[1],[2]
Balance (in Shares) at Dec. 31, 2013	118,900,000	'	'	'	'	'	118,888,876
Net income	'	'	284	'	'	12	296
Other comprehensive income	'	'	'	1	'	'	1
Dividends on common stock	'	'	-58	'	'	'	-58
Distributions to noncontrolling interest	'	'	'	'	'	-17	-17
Stock granted, share-based compensation, net of forfeitures	'	-11	'	'	'	'	-11
Stock issued, dividend reinvestment plan	'	2	'	'	'	'	2
Stock issued, share-based compensation, net of forfeitures	2	12	'	'	'	'	14
Stock issued, share-based compensation, net of forfeitures (in Shares)	300,000	'	'	'	'	'	'
Stock-based compensation expense, net of tax	'	3	'	'	'	'	3
Balance at Mar. 31, 2014	$597	$2,060	$1,289	($135)	($8)	$40	$3,843	[1],[2]
Balance (in Shares) at Mar. 31, 2014	119,200,000	'	'	'	'	'	119,247,421
[1]	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
[2]	Amounts revised to include prior period adjustments. See Note 13 for additional information.

Condensed_Consolidated_Stateme7

Condensed Consolidated Statements of Equity (Unaudited) (Parentheticals) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Dividends on common stock, per share	$0.49	$0.47

Condensed_Consolidated_Stateme8

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Cash flows from operating activities	'		'
Net income	$296		$160
Adjustments to reconcile net income to net cash flow provided by operating activities	'		'
Depreciation and amortization	93	[1]	102	[1]
Loss (income) from discontinued operations, net of taxes	50	[2],[3]	-1	[2],[3]
Deferred income taxes	8		-25
Change in derivative instrument assets and liabilities	-17		18
Changes in certain assets and liabilities	'		'
Inventories, net of temporary LIFO liquidation	656		494
Accrued expenses	182		30
Trade payables, other than energy marketing	52		-6
Energy marketing receivables and trade payables, net	8		87
Prepaid taxes	2		76
Receivables, other than energy marketing	-319		-167
Deferred/accrued natural gas costs	-228		43
Other, net	63		33
Net cash flow (used) provided by operating activities of discontinued operations	7		6
Net cash flow provided by operating activities	853		850
Cash flows from investing activities	'		'
Expenditures for property, plant and equipment	-161	[1]	-147	[1]
Acquisitions of assets	'		-122
Other, net	2		15
Net cash flow used in investing activities of discontinued operations	-5		-2
Net cash flow used in investing activities	-164		-256
Cash flows from financing activities	'		'
Net repayments of commercial paper	-430		-509
Dividends paid on common shares	-58		-55
Distribution to noncontrolling interest	-17		-17
Other, net	4		5
Net cash flow used in financing activities	-501		-576
Net increase in cash and cash equivalents – continuing operations	186		14
Net increase in cash and cash equivalents – discontinued operations	2		4
Cash and cash equivalents (including held for sale) at beginning of period	105		131
Cash and cash equivalents (including held for sale) at end of period	293		149
Less cash and cash equivalents held for sale at end of period	26		27
Cash and cash equivalents (excluding held for sale) at end of period	267		122
Cash paid during the period for	'		'
Interest	58		58
Income taxes	14		26
Non cash financing transaction	'		'
Refinancing of gas facility revenue bonds	'		$200
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
[3]	For additional information on our discontinued operations, see Note 12.

Note_1_Organization_and_Basis_

Note 1 - Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Disclosure Text Block [Abstract]	'
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	'
	Note 1 - Organization and Basis of Presentation
	General
	AGL Resources Inc. is an energy services holding company that conducts substantially all its operations through its subsidiaries. Unless the context requires otherwise, references to “we,” “us,” “our,” the “company,” or “AGL Resources” mean consolidated AGL Resources Inc. and its subsidiaries.
	The December 31, 2013 Condensed Consolidated Statement of Financial Position data was derived from our revised audited financial statements filed on November 7, 2014 but does not include all disclosures required by GAAP. We have prepared the accompanying unaudited Condensed Consolidated Financial Statements under the rules and regulations of the SEC. In accordance with such rules and regulations, we have condensed or omitted certain information and notes normally included in financial statements prepared in conformity with GAAP. Our unaudited Condensed Consolidated Financial Statements reflect all adjustments of a normal recurring nature that are, in the opinion of management, necessary for a fair presentation of our financial results for the interim periods. These unaudited Condensed Consolidated Financial Statements should be read in conjunction with our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A filed on November 7, 2014.
	Due to the seasonal nature of our business and other factors, our results of operations and our financial condition for the periods presented are not necessarily indicative of the results of operations and financial condition to be expected for or as of any other period.
	Basis of Presentation
	Our unaudited Condensed Consolidated Financial Statements include our accounts, the accounts of our wholly owned subsidiaries, the accounts of our majority owned or otherwise controlled subsidiaries and the accounts of our consolidated VIE for which we are the primary beneficiary. For unconsolidated entities that we do not control, but exercise significant influence over, we use the equity method of accounting and our proportionate share of income or loss is recorded on the unaudited Condensed Consolidated Statements of Income. See Note 9 for additional information. We have eliminated intercompany profits and transactions in consolidation except for intercompany profits where recovery of such amounts is probable under the affiliates’ rate regulation process.
	Revision of Previously-Issued Financial Statements We have revised our financial statements and other affected disclosures for items related to the recognition of revenues for certain of our regulatory infrastructure programs and the amortization of our intangible assets. We evaluated the cumulative impact of these items, together with other previously-identified adjustments for the same periods under the guidance in Accounting Standards Codification 250 Accounting Changes for Error Corrections (ASC 250) relating to SEC Staff Accounting Bulletin (SAB) No. 99, Materiality, and concluded that the revisions were not material, individually or in the aggregate, to any previously-issued quarterly or annual financial statements. We also evaluated the impact of revising these items through an adjustment to our financial statements for the quarter ended September 30, 2014 and concluded, based on the guidance within ASC 250 relating to SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements, to revise our previously-issued financial statements to reflect the impact of these revisions. Our prior-period financial statements have been revised in this Amended Filing. On November 7, 2014, we filed an amended Form 10-K/A revising certain prior period information with respect to our Annual Report on Form 10-K for the year ended December 31, 2013. See Note 13 for additional information.
	We previously disclosed in our Form 10-K/A that the revisions did not impact any incentive compensation that was based on our results for 2013, 2012 and 2011. However, subsequent to the filing of our Form 10-K/A, we determined that for 2011, had the underlying accounting originally reflected the distinction between regulatory accounting principles and GAAP, certain long-term incentives that were based on our results for the performance period ended December 31, 2011, would not have been awarded. Specifically, in February 2012, based upon results for the performance period ended December 31, 2011, we would not have awarded officers (as defined for purposes of Section 16 of the Securities Exchange Act of 1934, as amended) (1) performance cash unit awards with an aggregate value of approximately $1 million and (2) a total of 37,290 shares of restricted stock. Management has evaluated this item in relation to its previously filed Form 10-K/A and materiality conclusions under Staff Accounting Bulletin No. 99 and has concluded that it does not change its prior materiality conclusion.
	Discontinued Operations On April 4, 2014 we entered into a definitive agreement to sell Tropical Shipping, which historically operated within our cargo shipping segment. We closed on the sale of Tropical Shipping in September 2014. The assets and liabilities of these businesses are classified as held for sale on the unaudited Condensed Consolidated Statements of Financial Position, and the financial results of these businesses are reflected as discontinued operations on the unaudited Condensed Consolidated Statements of Income. Amounts shown in the following notes, unless otherwise indicated, exclude assets held for sale and discontinued operations. Cargo shipping also included our investment in Triton, which was not a part of the sale and has been reclassified into our “other” segment. See Note 12 for additional information.

Note_2_Significant_Accounting_

Note 2 - Significant Accounting Policies and Methods of Application	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Significant Accounting Policies [Text Block]	'
	Note 2 - Significant Accounting Policies and Methods of Application
	Our accounting policies are described in Note 2 to our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A. Other than as described in Note 13, there were no significant changes to our accounting policies during the three months ended March 31, 2014.
	Use of Accounting Estimates
	The preparation of our financial statements in conformity with GAAP requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and the related disclosures. Our estimates are based on historical experience and various other assumptions that we believe to be reasonable under the circumstances. Our estimates may involve complex situations requiring a high degree of judgment either in the application and interpretation of existing literature or in the development of estimates that impact our financial statements. The most significant estimates relate to our rate-regulated subsidiaries, uncollectible accounts and other allowances for contingent losses, goodwill and other intangible assets, retirement plan benefit obligations, derivative and hedging activities and provisions for income taxes. We evaluate our estimates on an ongoing basis and our actual results could differ from our estimates.
	Cash and Cash Equivalents
	Our cash and cash equivalents primarily consist of cash on deposit, money market accounts and certificates of deposit held by domestic subsidiaries with original maturities of three months or less. At March 31, 2014 and 2013, and December 31, 2013, there were $26 million, $27 million and $24 million, respectively, of cash and cash equivalents held by Tropical Shipping that were excluded from cash and cash equivalents within our unaudited Condensed Consolidated Statements of Financial Position and included in assets held for sale. For more information on the sale of Tropical Shipping, see Note 12.
	Energy Marketing Receivables and Payables
	Our wholesale services segment provides services to retail and wholesale marketers and utility and industrial customers. These customers, also known as counterparties, utilize netting agreements that enable our wholesale services segment to net receivables and payables by counterparty upon settlement. Wholesale services also nets across product lines and against cash collateral, provided the master netting and cash collateral agreements include such provisions. While the amounts due from, or owed to, wholesale services’ counterparties are settled net, they are recorded on a gross basis in our unaudited Condensed Consolidated Statements of Financial Position as energy marketing receivables and energy marketing payables.
	Our wholesale services segment has trade and credit contracts that contain minimum credit rating requirements. These credit rating requirements typically give counterparties the right to suspend or terminate credit if our credit ratings are downgraded to non-investment grade status. Under such circumstances, wholesale services would need to post collateral to continue transacting business with some of its counterparties. To date, our credit ratings have exceeded the minimum requirements. As of March 31, 2014 and 2013, and December 31, 2013, the collateral that wholesale services would have been required to post if our credit ratings had been downgraded to non-investment grade status would not have had a material impact to our consolidated results of operations, cash flows or financial condition. If such collateral were not posted, wholesale services’ ability to continue transacting business with these counterparties would be negatively impacted.
	Inventories
	For our regulated utilities, except Nicor Gas, our natural gas inventories and the inventories we hold for Marketers in Georgia are carried at cost on a WACOG basis. In Georgia’s competitive environment, Marketers sell natural gas to firm end-use customers at market-based prices. Part of the unbundling process, which resulted from deregulation and provides this competitive environment, is the assignment to Marketers of certain pipeline services that Atlanta Gas Light has under contract. On a monthly basis, Atlanta Gas Light assigns the majority of the pipeline storage services that it has under contract to Marketers, along with a corresponding amount of inventory. Atlanta Gas Light also retains and manages a portion of its pipeline storage assets and related natural gas inventories for system balancing and to serve system demand. See Note 10 for information regarding a regulatory filing by Atlanta Gas Light related to natural gas inventory.
	Nicor Gas’ inventory is carried at cost on a LIFO basis. Inventory decrements occurring during interim periods that are expected to be restored prior to year end are charged to cost of goods sold at the estimated annual replacement cost, and the difference between this cost and the actual liquidated LIFO layer cost is recorded as a temporary LIFO inventory liquidation. Any temporary LIFO liquidation is included as a current liability in our unaudited Condensed Consolidated Statements of Financial Position. Interim inventory decrements that are not expected to be restored prior to year end are charged to cost of goods sold at the actual LIFO cost of the layers liquidated. The inventory decrement as of March 31, 2014 is expected to be restored prior to year end. The inventory decrement as of March 31, 2013 was restored prior to December 31, 2013.
	Our retail operations, wholesale services and midstream operations segments carry inventory at the lower of cost or market value, where cost is determined on a WACOG basis. For these segments, we evaluate the weighted average cost of their natural gas inventories against market prices to determine whether any declines in market prices below the WACOG are other than temporary. For any declines considered to be other than temporary, we record adjustments to reduce the weighted average cost of the natural gas inventory to market value. For the three months ended March 31, 2014, wholesale services recorded a $2 million LOCOM adjustment to reduce the value of our inventories to market value. We recorded no LOCOM adjustment for the three months ended March 31, 2013.
	Fair Value Measurements
	We have financial and nonfinancial assets and liabilities subject to fair value measurement. The financial assets and liabilities measured and carried at fair value include cash and cash equivalents, and derivative assets and liabilities. The carrying values of receivables, short and long-term investments, accounts payable, short-term debt, other current assets and liabilities, and accrued interest approximate fair value. Our nonfinancial assets and liabilities include pension and other retirement benefits, which are presented in Note 4 to our Consolidated Financial Statements and in related notes included in Item 8 of our 2013 Form 10-K/A.
	As defined in the authoritative guidance related to fair value measurements and disclosures, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We utilize market data or assumptions that market participants would use in valuing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. We primarily apply the market approach for recurring fair value measurements to utilize the best available information. Accordingly, we use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. We classify fair value balances based on the observance of those inputs in accordance with the fair value hierarchy.
	Derivative Instruments
	The fair value of the natural gas and weather derivative instruments that we use to manage exposures arising from changing natural gas prices and weather risk reflects the estimated amounts that we would receive or pay to terminate or close the contracts at the reporting date, taking into account the current unrealized gains or losses on open contracts. We use external market quotes and indices to value substantially all of our derivative instruments. See Note 4 and Note 5 for additional derivative disclosures.
	Goodwill
	During the first quarter of 2014, we completed an engineering study at our storage and fuels reporting unit within midstream operations, which indicated a reduced forecast of working gas capacity from what was projected when our 2013 annual goodwill impairment analysis was performed during the fourth quarter of 2013. Given that the 2013 annual goodwill impairment test indicated that the estimated fair value of this reporting unit exceeded its carrying amount by less than 5%, we considered this reduced storage capacity as an indicator of potential impairment and, accordingly, conducted an interim goodwill impairment analysis during the first quarter of 2014.
	The estimated fair value of this reporting unit was determined utilizing the income approach, which estimated the fair value based upon the present value of estimated future cash flows. The forecasts used in the income approach, which were updated during the first quarter of 2014 to reflect the contracting activity that occurred during the quarter, assume discrete period revenue growth through fiscal 2022 to reflect the recovery of subscription rates, stabilization of earnings and establishment of a reasonable base year that was used to estimate the terminal value. Consistent with our 2013 annual goodwill impairment testing, we assumed a long-term earnings growth rate in the terminal year of 2.5%, which we believe is appropriate given the current economic and industry specific expectations. As of the valuation date, we utilized a discount rate of 7.0%, which we believe is appropriate as it reflects the relative risk and the time value of money, and is consistent with the peer group of this reporting unit as well as the discount rates that were utilized in our 2013 annual goodwill impairment tests.
	The cash flow forecasts for this reporting unit assumed earnings growth over the next eight years. Should this growth not occur, this reporting unit may fail step one during a future goodwill impairment test. Along with any reductions to our cash flow forecasts, changes in other assumptions used in our impairment analysis may require us to proceed to step two of the goodwill impairment test in a future period.
	Our interim goodwill impairment test indicated that the estimated fair value of this reporting unit continues to exceed its carrying amount with a cushion of less than 10%. Continued declines in capacity or subscription rates, a sustained period at the current subscription rates or other changes to the assumptions and factors used in this analysis may result in a future failure of step one of the goodwill impairment test. The risk of impairment of the underlying long-lived assets is not estimated to be significant as the assets have long remaining useful lives and authoritative guidance requires such assets to be tested for impairment on the basis of undiscounted cash flows over their remaining useful lives. We will continue to monitor this reporting unit for potential impairment. Our goodwill balances by segment as of March 31, 2014, and December 31, 2013, and changes in the amount of goodwill for the three months ended March 31, 2013, are provided in the following table.
	In millions		Distribution Operations			Retail			Midstream Operations		Consolidated
						Operations
	December 31, 2012 (1)		$	1,640		$	122		$	14	$	1,776
	2013 acquisitions			-			46			-		46
	March 31, 2013 (1)		$	1,640		$	168		$	14	$	1,822
	December 31, 2013 (1)		$	1,640		$	173		$	14	$	1,827
	March 31, 2014 (1)		$	1,640		$	173		$	14	$	1,827
	-1	Excludes goodwill at Tropical Shipping which is classified as held for sale. See Note 12 for additional information.
	Other Income
	Our other income is detailed in the following table. For more information on our equity investment income, see Note 9.
			Three months ended
			March 31,
	In millions		2014			2013
	Equity investment income		$	3		$	3
	AFUDC - equity			1			3
	Other, net			(1	)		(1	)
	Total other income		$	3		$	5
	Earnings Per Common Share
	We compute basic earnings per common share attributable to AGL Resources Inc. common shareholders by dividing our net income attributable to AGL Resources Inc. by the daily weighted average number of common shares outstanding. Diluted earnings per common share attributable to AGL Resources Inc. common shareholders reflect the potential reduction in earnings per common share attributable to AGL Resources Inc. common shareholders that occurs when potentially dilutive common shares are added to common shares outstanding.
	We derive our potentially dilutive common shares by calculating the number of shares issuable under restricted stock, restricted stock units and stock options. The vesting of certain shares of the restricted stock and restricted stock units depends on the satisfaction of defined performance and/or time based criteria. The future issuance of shares underlying the outstanding stock options depends on whether the market price of the common shares underlying the options exceeds the respective exercise prices of the stock options.
	The following table shows the calculation of our diluted shares attributable to AGL Resources Inc. common shareholders for the periods presented, if performance units currently earned under the plan ultimately vest and if stock options currently exercisable at prices below the average market prices are exercised.
			Three months ended March 31,
	In millions (except per share amounts)		2014 (1)			2013 (1)
	Income from continuing operations (2)		$	334		$	149
	(Loss) income from discontinued operations, net of tax (3)			(50	)		1
	Net income attributable to AGL Resources Inc.		$	284		$	150
	Denominator:
	Basic weighted average number of shares outstanding (4)			118.5			117.4
	Effect of dilutive securities			0.4			0.3
	Diluted weighted average number of shares outstanding			118.9			117.7
	Basic earnings (loss) per common share
	From continuing operations		$	2.82		$	1.27
	From discontinued operations			(0.43	)		0.01
	Basic earnings per common share attributable to AGL Resources Inc. common shareholders		$	2.39		$	1.28
	Diluted earnings (loss) per common share
	From continuing operations		$	2.81		$	1.26
	From discontinued operations			(0.43	)		0.01
	Diluted earnings per common share attributable to AGL Resources Inc. common shareholders		$	2.38		$	1.27
		-1	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
		-2	Excludes net income attributable to the noncontrolling interest.
	-3	For additional information on our discontinued operations, see Note 12.
	-4	Daily weighted average shares outstanding.
Accounting Developments
On April 10, 2014, the FASB issued authoritative guidance related to reporting discontinued operations. The guidance generally raises the threshold for disposals to qualify as discontinued operations and requires new disclosures of both discontinued operations and certain other material disposals that do not meet the definition of a discontinued operation. The guidance will be effective for us prospectively beginning January 1, 2015 and it is not expected to have a material impact on our consolidated financial statements nor will it have an impact on our accounting for the sale of Tropical Shipping. While permitted, we do not intend to adopt the guidance early.

Note_3_Regulated_Operations

Note 3 - Regulated Operations	3 Months Ended
	Mar. 31, 2014
Regulatory Assets and Liabilities Disclosure [Abstract]	'
Schedule of Regulatory Assets and Liabilities [Text Block]	'
	Note 3 - Regulated Operations
	We account for the financial effects of regulation in accordance with authoritative guidance related to regulated entities whose rates are designed to recover the costs of providing service. In accordance with this guidance, incurred costs and estimated future expenditures that would otherwise be charged to expense in the current period are capitalized as regulatory assets when it is probable that such costs or expenditures will be recovered in rates in the future. Similarly, we recognize regulatory liabilities when it is probable that regulators will require customer refunds through future rates or when revenue is collected from customers for estimated expenditures that have not yet been incurred. Generally, regulatory assets are amortized into expense and regulatory liabilities are amortized into income over the period authorized by the regulatory commissions. The following table summarizes our regulatory assets and liabilities as of the dates presented.
	In millions		March 31, 2014 (1)				December 31, 2013 (1)				March 31, 2013 (1)
	Regulatory assets
	Deferred natural gas costs		$	161			$	1			$	-
	Recoverable ERC			38				45				28
	Recoverable pension and retiree welfare benefit costs			9				9				19
	Other			42				59				25
	Total regulatory assets - current			250				114				72
	Recoverable ERC			419				433				415
	Recoverable pension and retiree welfare benefit costs			97				99				192
	Recoverable regulatory infrastructure program costs			57				55				125
	Long-term debt fair value adjustment			80				82				88
	Other			43				36				48
	Total regulatory assets - long-term			696				705				868
	Total regulatory assets		$	946			$	819			$	940
	Regulatory liabilities
	Bad debt over collection		$	41			$	41			$	39
	Accumulated removal costs			27				27				17
	Accrued natural gas costs			24				92				133
	Deferred seasonal rates			20				-				20
	Other			49				23				29
	Total regulatory liabilities - current			161				183				238
	Accumulated removal costs			1,456				1,445				1,413
	Regulatory income tax liability			27				27				26
	Unamortized investment tax credit			25				26				28
	Bad debt over collection			14				17				20
	Other			28				3				11
	Total regulatory liabilities - long-term			1,550				1,518				1,498
	Total regulatory liabilities		$	1,711			$	1,701			$	1,736
		-1	Amounts revised to include prior period adjustments. See Note 13 for additional information.
	Base rates are designed to provide the opportunity for both a recovery of cost and a return on investment during the period rates are in effect. As such, all of our regulatory assets recoverable through base rates are subject to review by the respective state regulatory commission during future rate proceedings. We believe that we will be able to recover such costs consistent with our historical recoveries.
	Unrecognized Ratemaking Amounts We have authorized unrecognized ratemaking amounts that are not reflected within our unaudited Condensed Consolidated Statements of Financial Position as indicated in the following table. These amounts are primarily composed of an allowed equity rate of return on assets associated with certain of our regulatory infrastructure programs. These amounts will be recognized as revenues in our financial statements in the periods they are collected in rates from our customers. For additional information, see Note 13.
	In millions
	31-Mar-14		$	102
	31-Dec-13		$	93
	31-Mar-13		$	71
	Natural Gas Costs We charge our utility customers for natural gas consumed using natural gas cost recovery mechanisms set by the state regulatory agencies. Under these mechanisms, all prudently incurred natural gas costs are passed through to customers without markup, subject to regulatory review. We defer or accrue the difference between the actual cost of gas and the amount of commodity revenue earned in a given period, such that no operating margin is recognized related to these costs. The deferred or accrued amount is either billed or refunded to our customers prospectively through adjustments to the commodity rate. Deferred natural gas costs are reflected as regulatory assets and accrued natural gas costs are reflected as regulatory liabilities. The following table illustrates the change in net position of these costs from March 31, 2013 to March 31, 2014.
	In millions		31-Mar-14				31-Mar-13				Change
	Deferred natural gas costs		$	161			$	-			$	161
	Accrued natural gas costs			(24	)			(133	)			109
	Total (1)		$	137			$	(133	)		$	270
		-1	The $270 million change resulted from increased natural gas prices during the first quarter of 2014 compared to the first quarter of 2013, primarily driven by colder weather experienced in the current quarter. These costs will be fully recovered in future periods.
	Environmental Remediation Costs We are subject to federal, state and local laws and regulations governing environmental quality and pollution control that require us to remove or remedy the effect on the environment of the disposal or release of specified substances at our current and former operating sites. The ERC assets and liabilities are associated with our distribution operations segment and are generally recoverable through rate mechanisms.
	Our ERC liabilities are estimates of future remediation costs for investigation and cleanup of our current and former operating sites that are contaminated. These estimates are based on conventional engineering estimates and the use of probabilistic models of potential costs when such estimates cannot be made, on an undiscounted basis. As cleanup options and plans mature and cleanup contracts are entered into, we are increasingly able to provide conventional engineering estimates of the likely costs of many elements of the remediation program. These estimates contain various engineering assumptions, which we refine and update on an ongoing basis. These liabilities do not include other potential expenses, such as unasserted property damage claims, personal injury or natural resource damage claims, legal expenses or other costs for which we may be held liable but for which we cannot reasonably estimate an amount. The following table provides additional information on the costs related to remediation of our current and former operating sites as of March 31, 2014 and reflects minor changes in estimates since December 31, 2013.
	In millions		Probabilistic model cost estimates		Engineering estimates				Amount recorded				Expected costs over next 12 months
	Illinois		$211 - $461		$	42			$	246			$	39
	New Jersey		139 - 233			6				144				25
	Georgia and Florida		28 - 112			8				39				10
	North Carolina		n/a			11				11				8
	Total		$378 - $806		$	67			$	440			$	82

Note_4_Fair_Value_Measurements

Note 4 - Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Disclosures [Text Block]	'
	Note 4 - Fair Value Measurements
	The methods used to determine the fair values of our assets and liabilities are described within Note 2.
	Derivative Instruments
	The following table summarizes, by level within the fair value hierarchy, our derivative assets and liabilities that were carried at fair value on a recurring basis in our unaudited Consolidated Statements of Financial Position as of the dates presented. See Note 5 for additional derivative instrument information.
			31-Mar-14					31-Dec-13					31-Mar-13
	In millions		Assets (1)		Liabilities			Assets (1)		Liabilities			Assets (1)		Liabilities
	Natural gas derivatives
	Quoted prices in active markets (Level 1)		$	18	$	(38	)	$	6	$	(79	)	$	14	$	(38	)
	Significant other observable inputs (Level 2)			50		(75	)		67		(79	)		49		(23	)
	Netting of cash collateral			69		31			43		78			40		37
	Total carrying value (2) (3)		$	137	$	(82	)	$	116	$	(80	)	$	103	$	(24	)
	Interest rate derivatives
	Significant other observable inputs (Level 2)		$	-	$	-		$	-	$	-		$	6	$	-
		-1	Balances of $1 million at March 31, 2014, $3 million at December 31, 2013 and $2 million at March 31, 2013 associated with certain weather derivatives have been excluded, as they are accounted for based on intrinsic value rather than fair value.
		-2	There were no significant unobservable inputs (Level 3) for any of the dates presented.
		-3	There were no significant transfers between Level 1, Level 2 or Level 3 for any of the dates presented.
	Debt
	Our long-term debt is recorded at amortized cost, with the exception of Nicor Gas’ first mortgage bonds, which are recorded at their acquisition date fair value. The fair value adjustment of Nicor Gas’ first mortgage bonds is being amortized over the lives of the bonds. The following table presents the carrying amount and fair value of our long-term debt as of the following dates.
	In millions		31-Mar-14		31-Dec-13			31-Mar-13
	Long-term debt carrying amount		$	3,810	$	3,813		$	3,550
	Long-term debt fair value (1)			4,095		3,956			4,006
		-1	Fair value determined using Level 2 inputs.

Note_5_Derivative_Instruments

Note 5 - Derivative Instruments	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Hedging Activities Disclosure [Text Block]	'
	Note 5 - Derivative Instruments
	A description of our objectives and strategies for using derivative instruments, related accounting policies and methods used to determine their fair values are described in Note 2 to our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A. See Note 4 for additional fair value disclosures.
	Certain of our derivative instruments contain credit-risk-related or other contingent features that could require us to post collateral in the normal course of business when our financial instruments are in net liability positions. As of March 31, 2014, for agreements with such features, derivative instruments with liability fair values totaled $82 million, for which we had posted no collateral to our counterparties. The maximum collateral that could be required with these features is $15 million. For more information, see “Energy Marketing Receivables and Payables” in Note 2, which also have credit-risk-related or other contingent features. Our derivative instrument activities are included within operating cash flows as an adjustment to net income of ($17) million and $18 million for the three months ended March 31, 2014 and 2013, respectively. See Note 4 for additional derivative instrument information. The following table summarizes the various ways in which we account for our derivative instruments and the impact on our unaudited Condensed Consolidated Financial Statements.
		Recognition and Measurement
	Accounting Treatment	Statements of Financial Position	Statements of Income
	Cash flow hedge	Derivative carried at fair value	Ineffective portion of the gain or loss on the derivative instrument is recognized in earnings
		Effective portion of the gain or loss on the derivative instrument is reported initially as a component of accumulated OCI (loss)	Effective portion of the gain or loss on the derivative instrument is reclassified out of accumulated OCI (loss) and into earnings when the hedged transaction affects earnings
	Fair value hedge	Derivative carried at fair value	Gains or losses on the derivative instrument and the hedged item are recognized in earnings. As a result, to the extent the hedge is effective, the gains or losses will offset and there is no impact on earnings. Any hedge ineffectiveness will impact earnings
		Changes in fair value of the hedged item are recorded as adjustments to the carrying amount of the hedged item
	Not designated as hedges	Derivative carried at fair value	Realized and unrealized gains or losses on the derivative instrument are recognized in earnings
		Distribution operations’ gains and losses on derivative instruments are deferred as regulatory assets or liabilities until included	Gains or losses on these derivative instruments are ultimately included in billings to customers and are recognized in cost of goods sold in the same period as the related revenues
		in cost of goods sold
	Quantitative Disclosures Related to Derivative Instruments
	As of the dates presented, our derivative instruments were comprised of both long and short natural gas positions. A long position is a contract to purchase natural gas, and a short position is a contract to sell natural gas. We had a net long natural gas contracts position outstanding in the following quantities:
	In Bcf (1)		March 31, 2014 (2)				31-Dec-13				31-Mar-13
	Hedge designation
	Cash flow hedges			6				6				6
	Not designated as hedges			277				183				304
	Total hedges			283				189				310
	Hedge position
	Short position			(2,491	)			(2,622	)			(1,902	)
	Long position			2,774				2,811				2,212
	Net long position			283				189				310
	-1	Volumes related to Nicor Gas exclude variable-priced contracts, which are carried at fair value, but whose fair values are not directly impacted by changes in commodity prices.
	-2	Approximately 97% of these contracts have durations of two years or less and the remaining 3% expire between 2 and 5 years.
	Derivative Instruments in our Unaudited Condensed Consolidated Statements of Financial Position
	In accordance with regulatory requirements, gains and losses on derivative instruments used to hedge natural gas purchases for customer use at Nicor Gas and Elizabethtown Gas are reflected in accrued natural gas costs within our Consolidated Statements of Financial Position until billed to customers. The following amounts represent the net realized gains (losses) related to these natural gas cost hedges for the periods presented.
			Three months ended March 31,
	In millions		2014				2013
	Nicor Gas		$	2			$	(1	)
	Elizabethtown Gas			3				(3	)
	The following table presents the fair values and unaudited Condensed Consolidated Statements of Financial Position classifications of our derivative instruments as of the dates presented.
				March 31,								31-Dec-13						March 31,
				2014														2013
	In millions	Classification		Assets				Liabilities				Assets			Liabilities			Assets			Liabilities
	Designated as cash flow hedges and fair value hedges
	Natural gas contracts	Current		$	2			$	-			$	3		$	(1	)	$	3		$	(1	)
	Interest rate swap agreements	Current			-				-				-			-			5			-
	Total				2				-				3			(1	)		8			(1	)
	Not designated as cash flow hedges
	Natural gas contracts	Current			675				(703	)			691			(761	)		332			(327	)
	Natural gas contracts	Long-term			80				(98	)			206			(220	)		46			(48	)
	Total				755				(801	)			897			(981	)		378			(375	)
	Gross amount of recognized assets and liabilities (1)				757				(801	)			900			(982	)		386			(376	)
	Gross amounts offset in our unaudited Condensed Consolidated Statements of Financial Position (2)				(619	)			719				(781	)		902			(275	)		352
	Net amounts of assets and liabilities presented in our unaudited Condensed Consolidated Statements of Financial Position (3)			$	138			$	(82	)		$	119		$	(80	)	$	111		$	(24	)
	-1	The gross amounts of recognized assets and liabilities are netted within our unaudited Condensed Consolidated Statements of Financial Position to the extent that we have netting arrangements with the counterparties.
	-2	As required by the authoritative guidance related to derivatives and hedging, the gross amounts of recognized assets and liabilities above do not include cash collateral held on deposit in broker margin accounts of $100 million as of March 31, 2014, $121 million as of December 31, 2013 and $77 million as of March 31, 2013. Cash collateral is included in the “Gross amounts offset in our unaudited Condensed Consolidated Statements of Financial Position” line of this table.
	-3	At March 31, 2014, December 31, 2013 and March 31, 2013 we held letters of credit from counterparties that would offset, under master netting arrangements, an insignificant portion of these assets.
	Derivative Instruments in the UnauditedCondensed Consolidated Statements of Income
	The following table presents the impacts of our derivative instruments in our unaudited Condensed Consolidated Statements of Income for the periods presented.
			Three months ended March 31,
	In millions		2014				2013
	Designated as cash flow hedges
	Natural gas contracts - net gain reclassified from OCI to cost of goods sold		$	3			$	-
	Natural gas contracts - net gain reclassified from OCI to operation and maintenance expense			1				-
	Interest rate swaps - loss reclassified from OCI to interest expense			-				(3	)
	Income tax benefit			-				1
	Net of tax			4				(2	)
	Not designated as hedges (1)
	Natural gas contracts - net fair value adjustments recorded in operating revenues			(30	)			(24	)
	Natural gas contracts - net fair value adjustments recorded in cost of goods sold (2)			2				-
	Income tax benefit			11				8
Net of tax			(17	)			(16	)
Total losses on derivative instruments, net of tax		$	(13	)		$	(18	)
	-1	Associated with the fair value of derivative instruments held at March 31, 2014 and 2013.
	-2	Excludes losses recorded in cost of goods sold associated with weather derivatives of $5 million for the three months ended March 31, 2014 and $2 million for the three months ended March 31, 2013.
Any amounts recognized in operating income, related to ineffectiveness or due to a forecasted transaction that is no longer expected to occur were immaterial for the three months ended March 31, 2014 and 2013.
Our expected gains to be reclassified from OCI into cost of goods sold, operation and maintenance expense, interest expense and operating revenues and recognized in our unaudited Condensed Consolidated Statements of Income over the next 12 months are $3 million. These deferred gains and losses are related to natural gas derivative contracts associated with retail operations and Nicor Gas’ system use. The expected gains are based upon the fair values of these financial instruments at March 31, 2014.
There have been no other significant changes to our derivative instruments, as described in Note 2, Note 4 and Note 5 to our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A.

Note_6_Employee_Benefit_Plans

Note 6 - Employee Benefit Plans	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Pension and Other Postretirement Benefits Disclosure [Text Block]	'
	Note 6 - Employee Benefit Plans
	Pension Benefits
	We sponsor the AGL Resources Inc. Retirement Plan, a tax-qualified defined benefit retirement plan for our eligible employees, which is described in Note 6 to our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A. Following are the components of our pension costs for the periods indicated.
		Three months ended March 31,
	In millions	2014			2013
	Service cost	$	6		$	8
	Interest cost		12			10
	Expected return on plan assets		(16	)		(16	)
	Recognized actuarial loss		5			8
	Net periodic pension benefit cost	$	7		$	10
	Welfare Benefits
	The benefits of our Health and Welfare Plan for Retirees and Inactive Employees of AGL Resources Inc. (AGL Welfare Plan) are described in Note 6 to our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A. Following are the components of our welfare costs for the periods indicated.
		Three months ended March 31,
	In millions	2014			2013
	Service cost	$	1		$	1
	Interest cost		4			3
	Expected return on plan assets		(2	)		(1	)
	Net amortization of prior service cost		(1	)		(1	)
	Recognized actuarial loss		1			2
	Net periodic welfare benefit cost	$	3		$	4

Note_7_Debt_and_Credit_Facilit

Note 7 - Debt and Credit Facilities	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Debt Disclosure [Text Block]	'
	Note 7 - Debt and Credit Facilities
	The following table provides maturity dates, year-to-date weighted average interest rates and amounts outstanding for our various debt securities and facilities for the periods presented. We fully and unconditionally guarantee all debt issued by AGL Capital. For additional information on our debt, see Note 8 in our Consolidated Financial Statements and related notes in Item 8 of our 2013 Form 10-K/A.
						31-Mar-14								31-Mar-13
	Dollars in millions		Year(s) due			Weighted average			Outstanding			Outstanding at December 31, 2013		Weighted average			Outstanding
						interest rate (1)								interest rate (1)
	Short-term debt
	Commercial paper - AGL Capital (2)		2014				0.3	%	$	440		$	857		0.5	%	$	868
	Commercial paper - Nicor Gas (2)		2014				0.2			301			314		0.4			-
	Total short-term debt						0.3			741			1,171		0.5			868
	Current portion of long-term debt and capital leases
	Current portion of long-term debt		2015				5			200			-		4.5			225
	Current portion of capital leases		n/a				-			-			-		5			1
	Total current portion of long-term debt and capital leases						5	%	$	200		$	-		4.5	%	$	226
	Long-term debt - excluding current portion
	Senior notes		2016-2043				5	%	$	2,625		$	2,825		5.1	%	$	2,325
	First mortgage bonds		2016-2038				5.6			500			500		5.6			500
	Gas facility revenue bonds		2022-2033				0.9			200			200		1.2			200
	Medium-term notes		2017-2027				7.8			181			181		7.8			181
	Total principal long-term debt						4.9	%		3,506			3,706		5	%		3,206
	Fair value adjustment of long-term debt (3)		2016-2038			n/a				88			91	n/a				100
	Unamortized debt premium, net		n/a			n/a				16			16	n/a				18
	Total non-principal long-term debt					n/a				104			107	n/a				118
	Total long-term debt								$	3,610		$	3,813				$	3,324
	Total debt								$	4,551		$	4,984				$	4,418
	-1	Interest rates are calculated based on the daily weighted average balance outstanding for the three months ended March 31.
	-2	As of March 31, 2014, the effective interest rates on our commercial paper borrowings were 0.3% for AGL Capital and 0.2% for Nicor Gas.
	-3	See Note 4 for additional information on our fair value measurements.
	Commercial Paper Programs
	We maintain commercial paper programs at AGL Capital and Nicor Gas that consist of short-term, unsecured promissory notes used in conjunction with cash from operations to fund our seasonal working capital requirements. Working capital needs fluctuate during the year and are highest during the injection period in advance of the Heating Season. The Nicor Gas commercial paper program supports working capital needs at Nicor Gas, while all of our other subsidiaries and SouthStar participate in the AGL Capital commercial paper program. During the first quarter of 2014, our commercial paper maturities ranged from 1 to 108 days, and at March 31, 2014, remaining terms to maturity ranged from 1 to 35 days. Total borrowings and repayments netted to a payment of $430 million during the first quarter of 2014. For commercial paper issuances with original maturities over 3 months, borrowings and repayments were $50 million and $145 million, respectively, during the first quarter of 2014.
	Financial and Non-Financial Covenants
	The AGL Credit Facility and the Nicor Gas Credit Facility each include a financial covenant that requires us to maintain a ratio of total debt to total capitalization of no more than 70% at the end of any fiscal month. These ratios, as calculated in accordance with the debt covenants, include standby letters of credit and surety bonds and exclude accumulated OCI items related to non-cash pension adjustments, welfare benefits liability adjustments and accounting adjustments for cash flow hedges. Adjusting for these items, the following table contains our debt-to-capitalization ratios for the dates presented, which are below the maximum allowed.
			31-Mar-14			31-Dec-13			31-Mar-13
	AGL Credit Facility			54	%		57	%		55	%
	Nicor Gas Credit Facility			54	%		55	%		43	%
	The credit facilities contain certain non-financial covenants that, among other things, restrict liens and encumbrances, loans and investments, acquisitions, dividends and other restricted payments, asset dispositions, mergers and consolidations and other matters customarily restricted in such agreements.
	Default Provisions
	Our credit facilities and other financial obligations include provisions that, if not complied with, could require early payment or similar actions. The most important default events include:
		●	a maximum leverage ratio
		●	insolvency events and nonpayment of scheduled principal or interest payments
		●	acceleration of other financial obligations
		●	change of control provisions
	We have no triggering events in our debt instruments that are tied to changes in our specified credit ratings or our stock price, and have not entered into any transaction that requires us to issue equity based on credit ratings or other triggering events. We were in compliance with all existing debt provisions and covenants, both financial and non-financial, for all periods presented.

Note_8_Equity

Note 8 - Equity	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity Note Disclosure [Text Block]	'
	Note 8 - Equity
	Our OCI amounts are aggregated within our accumulated other comprehensive loss. The following table provides changes in the components of our accumulated other comprehensive loss balance, net of the related income tax effects.
	In millions (1)		Cash flow hedges			Retirement benefit plans			Total
	As of December 31, 2012		$	(3	)	$	(215	)	$	(218	)
	OCI, before reclassifications			2			-			2
	Amounts reclassified from accumulated OCI			2			3			5
	As of March 31, 2013			1			(212	)		(211	)
	As of December 31, 2013			1			(137	)		(136	)
	OCI, before reclassifications			4			-			4
	Amounts reclassified from accumulated OCI			(4	)		1			(3	)
	As of March 31, 2014		$	1		$	(136	)	$	(135	)
		-1	All amounts are net of income taxes. Amounts in parentheses indicate debits to accumulated other comprehensive loss.
	The following table provides details of the reclassifications out of accumulated other comprehensive loss and the impact on net income.
			Three months ended March 31,
	In millions (1)		2014			2013
	Cash flow hedges
	Natural gas contracts (2)		$	4		$	-
	Interest rate contracts (3)			-			(3	)
	Total before income tax			4			(3	)
	Income tax benefit			-			1
	Total cash flow hedges			4			(2	)
	Retirement benefit plan amortization of
	Actuarial losses (4)			(2	)		(6	)
	Prior service credits (4)			-			1
	Total before income tax			(2	)		(5	)
	Income tax benefit			1			2
	Total retirement benefit plans			(1	)		(3	)
	Total reclassification for the period		$	3		$	(5	)
		-1	Amounts in parentheses indicate debits, or reductions, to profit/loss and credits to accumulated other comprehensive loss. Except for retirement benefit plan amounts, the profit/loss impacts are immediate.
		-2	Amounts included within cost of goods sold.
		-3	Amounts included within interest expense, net.
		-4	Amortization of these accumulated other comprehensive loss components is included in the computation of net periodic benefit cost. See Note 6 for additional details about net periodic benefit cost.

Note_9_NonWholly_Owned_Entitie

Note 9 - Non-Wholly Owned Entities	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
Noncontrolling Interest Disclosure [Text Block]	'
	Note 9 - Non-Wholly Owned Entities
	Variable Interest Entities
	SouthStar, a joint venture owned by us and Piedmont, is our only VIE for which we are the primary beneficiary, which requires us to consolidate its assets, liabilities and statements of income. See Note 10 to our Consolidated Financial Statements and related notes included in Item 8 of our 2013 Form 10-K/A. Earnings from SouthStar in 2014 and 2013 were allocated entirely in accordance with the ownership interests.
	Cash flows used in our investing activities include capital expenditures for SouthStar of $2 million for the three months ended March 31, 2014 and $1 million for the three months ended March 31, 2013. Cash flows used in our financing activities include SouthStar’s distribution to Piedmont for its portion of SouthStar’s annual earnings from the previous year. Generally, this distribution occurs in the first quarter of each fiscal year. For each of the three months ended March 31, 2014 and 2013, SouthStar distributed $17 million to Piedmont. The following table provides additional information about SouthStar’s assets and liabilities as of the dates presented, which are consolidated within our unaudited Condensed Consolidated Statements of Financial Position.
			March 31, 2014 (1) (2)							December 31, 2013 (1) (2)							March 31, 2013 (1) (2)
	In millions		Consolidated		SouthStar(3)		-4%			Consolidated		SouthStar(3)		-4%			Consolidated		SouthStar(3)		-4%
	Current assets		$	3,589	$	235		7	%	$	2,895	$	264		9	%	$	2,530	$	143		6	%
	Goodwill and other intangible assets			1,967		131		7			1,972		133		7			1,953		-		-
	Long-term assets and other deferred debits			9,708		16		-			9,683		13		-			9,379		10		-
	Total assets		$	15,264	$	382		3	%	$	14,550	$	410		3	%	$	13,862	$	153		1	%
	Current liabilities		$	3,754	$	106		3	%	$	3,118	$	95		3	%	$	3,059	$	51		2	%
	Long-term liabilities and other deferred credits			7,667		-		-			7,819		-		-			7,310		-		-
	Total Liabilities			11,421		106		1			10,937		95		1			10,369		51		-
	Equity			3,843		276		7			3,613		315		9			3,493		102		3
	Total liabilities and equity		$	15,264	$	382		3	%	$	14,550	$	410		3	%	$	13,862	$	153		1	%
	-1	Amounts revised to include prior period adjustments. See Note 13 for additional information.
	-2	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
	-3	These amounts reflect information for SouthStar and exclude intercompany eliminations and the balances of our wholly owned subsidiary with an 85% ownership interest in SouthStar.
	-4	SouthStar’s percentage of the amount on our Statements of Financial Position.
	The following table provides information on SouthStar’s operating revenues and operating expenses for the periods presented, which are consolidated within our unaudited Condensed Consolidated Statements of Income.
			Three months ended March 31,
	In millions		2014 (1)		2013 (1)
	Operating revenues		$	374	$	250
	Operating expenses
	Cost of goods sold			270		164
	Operation and maintenance			23		18
	Depreciation and amortization			3		1
	Total operating expenses			296		183
	Operating income		$	78	$	67
	-1	Amounts revised to include prior period adjustments. See Note 13 for additional information.
	Equity Method Investments
	Income from our equity method investments is classified as other income in our unaudited Condensed Consolidated Statements of Income. For more information about our equity method investments, see Note 10 to our Consolidated Financial Statements and related notes in Item 8 of our 2013 Form 10-K/A.
	The carrying amounts of our investments that are accounted for under the equity method at March 31 were as follows:
	In millions		2014		2013
	Triton		$	67	$	72
	Horizon Pipeline			15		16
	Other (1)			1		9
	Total		$	83	$	97
		-1	Includes our investment in Sawgrass Storage. In December 2013, the joint venture decided to terminate the development of the Sawgrass storage facility and reduced the carrying amount of the joint venture’s long-lived assets to fair value.
	The following table provides the income from our equity method investments for the three months ended March 31.
	In millions		2014		2013
	Triton		$	2	$	2
	Horizon Pipeline			1		1
	Total		$	3	$	3

Note_10_Commitments_Guarantees

Note 10 - Commitments, Guarantees and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies Disclosure [Text Block]	'
	Note 10 - Commitments, Guarantees and Contingencies
	We have incurred various contractual obligations and financial commitments in the normal course of our operating and financing activities that are reasonably likely to have a material effect on liquidity or the availability of capital resources. Contractual obligations include future cash payments required under existing contractual arrangements, such as debt and lease agreements. These obligations may result from both general financing activities and from commercial arrangements that are directly supported by related revenue-producing activities.
	We also are involved in legal or administrative proceedings before various courts and agencies with respect to general claims, taxes, environmental, gas cost prudence reviews and other matters. Although we are unable to determine the ultimate outcomes of these other contingencies, we believe that our financial statements appropriately reflect these amounts, including the recording of liabilities when a loss is probable and reasonably estimable. For more information on these matters, see Note 11 in our Consolidated Financial Statements and related notes in Item 8 of our 2013 Form 10-K/A.
	Contingencies and Guarantees
	Contingent financial commitments, such as financial guarantees, represent obligations that become payable only if certain predefined events occur. We have certain subsidiaries that enter into various financial and performance guarantees and indemnities providing assurance to third parties. We believe the likelihood of payment under our guarantees is remote. No liability has been recorded for such guarantees and indemnifications as the fair value is immaterial.
	Regulatory Matters
	On December 21, 2012 Atlanta Gas Light filed a petition with the Georgia Commission for approval to resolve an imbalance of approximately 4.8 Bcf of natural gas related to Atlanta Gas Light’s use of retained storage assets to operationally balance the system for the benefit of the natural gas market. We believe that any costs associated with resolving the imbalance are recoverable from Marketers. We are currently working with the Marketers to settle this matter, and the resolution of this imbalance will ultimately be decided by the Georgia Commission. We are currently unable to predict the ultimate outcome and recovery.
	Environmental Matters
	We are subject to federal, state and local laws and regulations governing environmental quality and pollution control that require us to remove or remedy the effect on the environment of the disposal or release of specified substances at our current and former operating sites. See Note 3 for additional information.
	Litigation
	We are involved in litigation arising in the normal course of business. Although in some cases the company is unable to estimate the amount of loss reasonably possible in addition to any amounts already recognized, it is possible that the resolution of these contingencies, either individually or in aggregate, will require us to take charges against, or will result in reductions in, future earnings. Management believes that while the resolution of these contingencies, whether individually or in aggregate, could be material to earnings in a particular period, they will not have a material adverse effect on our consolidated financial position or cash flows. For additional litigation information, see Note 11 in our Consolidated Financial Statements and related notes in Item 8 of our 2013 Form 10-K/A.
	PBR Proceeding Nicor Gas’ PBR plan was a regulatory plan that provided economic incentives based on natural gas cost performance. The PBR plan went into effect in 2000 and was terminated effective January 1, 2003, following allegations that Nicor Gas acted improperly in connection with the plan. Under this plan, Nicor Gas’ total gas supply costs were compared to a market-sensitive benchmark. Savings and losses relative to the benchmark were determined annually and shared equally with sales customers. Since 2002 the amount of the savings and losses required to be shared has been disputed by the Citizens Utility Board (CUB) and others, with the Illinois Attorney General (IAG) intervening, and subject to extensive contested discovery and other regulatory proceedings before administrative law judges and the Illinois Commission. In 2009, the staff of the Illinois Commission, IAG and CUB requested refunds of $85 million, $255 million and $305 million, respectively.
	In February 2012 we committed to a stipulation with the staff of the Illinois Commission for a resolution of the dispute through the crediting to Nicor Gas customers of $64 million. On November 5, 2012 the Administrative Law Judges issued a proposed order for a refund of $72 million to ratepayers. In the fourth quarter of 2012, we increased our accrual for this dispute by $8 million for a total of $72 million as a result of these developments and their effect on the estimated liability.
	On June 7, 2013 the Illinois Commission issued an order requiring us to refund $72 million to current Nicor Gas customers over a 12-month period. On July 1, 2013 we began refunding customers the full $72 million through our purchased gas adjustment mechanism based on natural gas throughput. Of this amount, $35 million was refunded during the first quarter of 2014 and $29 million was refunded in 2013.
	CUB appealed the Illinois Commission’s order to the appellate court in Illinois. On February 28, 2014 CUB filed its initial brief with the appellate court requesting refunds consistent with its 2009 request. Nicor Gas’ reply is due May 16, 2014.

Note_11_Segment_Information

Note 11 - Segment Information	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segment Reporting Disclosure [Text Block]	'
	Note 11 - Segment Information
	Our operating segments comprise revenue-generating components of our company for which we produce separate financial information internally that is regularly used to make operating decisions and assess performance. Our determination of reportable segments considers the strategic operating units under which we manage sales of various products and services to customers in differing regulatory environments. We manage our businesses through four operating segments - distribution operations, retail operations, wholesale services and midstream operations - and other, a non-operating segment.
	On April 4, 2014 we entered into a definitive agreement to sell Tropical Shipping, which historically operated within our cargo shipping segment. The assets and liabilities of these businesses are classified as held for sale on the Consolidated Statements of Financial Position, and the financial results of these businesses are reflected as discontinued operations on the Consolidated Statements of Income. Amounts shown in this note, unless otherwise indicated, exclude assets held for sale and discontinued operations. Cargo shipping also included our investment in Triton, which was not part of the sale and has been reclassified into our “other” segment. See Note 12 for additional information. Our “other” segment includes aggregated subsidiaries that are not significant on a stand-alone basis and that do not fit into one of our other four operating segments.
	Our distribution operations segment is the largest component of our business and includes natural gas local distribution utilities in seven states. These utilities construct, manage and maintain intrastate natural gas pipelines and distribution facilities. Although the operations of our distribution operations segment are geographically dispersed, the operating subsidiaries within the distribution operations segment are regulated utilities, with rates determined by individual state regulatory commissions. These natural gas distribution utilities have similar economic and risk characteristics.
	We are also involved in several related and complementary businesses. Our retail operations segment includes retail natural gas marketing to end-use customers primarily in Georgia, as well as various businesses that market retail energy-related products and services to residential and small business customers in Illinois. Additionally, retail operations provide home protection products and services. Our wholesale services segment engages in natural gas storage and gas pipeline arbitrage and related activities. Additionally, they provide natural gas asset management and/or related logistics services for each of our utilities except Nicor Gas, as well as for nonaffiliated companies. Our midstream operations segment includes our non-utility storage and pipeline operations, including the operation of high-deliverability natural gas storage assets.
	The chief operating decision maker of the company is the Chairman, President and Chief Executive Officer who utilizes EBIT as the primary measure of profit and loss in assessing the results of our segments and operations. EBIT includes operating income and other income and expenses. Items we do not include in EBIT are income taxes and financing costs, including interest expense, each of which we evaluate on a consolidated basis.
	Information by segment on our Statements of Financial Position as of December 31, 2013 is as follows:
	In millions		Identifiable and			Goodwill
			total assets (1) (2)
	Distribution operations		$	11,634		$	1,640
	Retail operations			685			173
	Wholesale services			1,163			-
	Midstream operations			713			14
	Other (3)			10,160			-
	Intercompany eliminations			(10,088	)		-
	Consolidated		$	14,267		$	1,827
		-1	Amounts revised to include prior period adjustments. See Note 13 for additional information.
		-2	Identifiable assets are those assets used in each segment’s operations and exclude assets held for sale.
		-3	Includes our investment in Triton, which was part of our cargo shipping segment that is classified as discontinued operations. For more information see Note 12.
	Summarized Statements of Income, Statements of Financial Position and capital expenditure information by segment as of and for the periods presented are shown in the following tables.
	Three months ended March 31, 2014 (1)
	In millions		Distributionoperations			Retail operations		Wholesale services (2)		Midstream operations			Other (4)			Intercompany eliminations			Consolidated
	Operating revenues from external parties		$	1,726		$	406	$	331	$	44		$	3		$	(48	)	$	2,462
	Intercompany revenues			75			-		-		-			-			(75	)		-
	Total operating revenues			1,801			406		331		44			3			(123	)		2,462
	Operating expenses
	Cost of goods sold			1,202			280		3		36			-			(121	)		1,400
	Operation and maintenance			211			37		36		6			1			(2	)		289
	Depreciation and amortization			78			8		-		5			2			-			93
	Taxes other than income taxes			82			1		1		1			3			-			88
	Total operating expenses			1,573			326		40		48			6			(123	)		1,870
	Operating income (loss)			228			80		291		(4	)		(3	)		-			592
	Other income			1			-		-		1			1			-			3
	EBIT		$	229		$	80	$	291	$	(3	)	$	(2	)	$	-		$	595
	Identifiable and total assets (3)		$	11,823		$	738	$	1,782	$	698		$	9,844		$	(9,885	)	$	15,000
	Capital expenditures		$	150		$	3	$	1	$	-		$	7		$	-		$	161
	Three months ended March 31, 2013 (1)
	In millions		Distributionoperations			Retail operations		Wholesale services (2)		Midstream operations			Other (4)			Intercompany eliminations			Consolidated
	Operating revenues from external parties		$	1,255		$	302	$	39	$	24		$	1		$	(9	)	$	1,612
	Intercompany revenues			55			-		-		-			-			(55	)		-
	Total operating revenues			1,310			302		39		24			1			(64	)		1,612
	Operating expenses
	Cost of goods sold			765			195		10		12			-			(62	)		920
	Operation and maintenance			185			31		13		6			(2	)		(2	)		231
	Depreciation and amortization			88			6		-		4			4			-			102
	Taxes other than income taxes			64			1		1		1			2			-			69
	Total operating expenses			1,102			233		24		23			4			(64	)		1,322
	Operating income (loss)			208			69		15		1			(3	)		-			290
	Other income			3			-		-		1			1			-			5
	EBIT		$	211		$	69	$	15	$	2		$	(2	)	$	-		$	295
	Identifiable and total assets (3)		$	11,188		$	663	$	1,005	$	714		$	9,732		$	(9,731	)	$	13,571
	Capital expenditures		$	137		$	1	$	-	$	4		$	5		$	-		$	147
	-1	Amounts revised to include prior period adjustments. See Note 13 for additional information.
	-2	Wholesale services records its energy marketing and risk management revenues on a net basis. A reconciliation of our operating revenues and our intercompany revenues is shown in the following table.
	In millions		Third party gross revenues			Intercompany revenues		Total gross revenues		Less gross			Operating revenues
										gas costs
	Three months ending March 31, 2014		$	4,049		$	298	$	4,347	$	4,016		$	331
	Three months ending March 31, 2013			2,094			140		2,234		2,195			39
	-3	Identifiable assets are those used in each segment’s operations and exclude assets held for sale.
	-4	Our “other” segment now also includes our investment in Triton, which was part of our cargo shipping segment that is classified as discontinued operations. For more information see Note 12.

Note_12_Discontinued_Operation

Note 12 - Discontinued Operations	3 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	'
	Note 12 - Discontinued Operations
	On September 1, 2014, we closed on the sale of Tropical Shipping to an unrelated third party. The after-tax cash proceeds and distributions from the transaction were $225 million. We determined that the cumulative foreign earnings of Tropical Shipping would no longer be indefinitely reinvested offshore. Accordingly, we recognized income tax expense of $60 million, of which $31 million was recorded in the first quarter of 2014, and the remaining $29 million was recorded in the third quarter of 2014 related to the cumulative foreign earnings for which no tax liabilities had been previously recorded, resulting in our repatriation of $86 million in cash.
	24
	During the first quarter of 2014, based upon the negotiated sales price, we also recorded a goodwill impairment charge of $19 million, for which there is no income tax benefit.
	Our financial statements, including footnotes 1, 2, 4, 9 and 11 have been updated to recast our segment information and to give effect to the classification of Tropical Shipping as discontinued operations for all periods presented. The assets and liabilities of Tropical Shipping classified as held for sale on the unaudited Condensed Consolidated Statements of Financial Position are as follows:
			March 31,			December 31,		March 31,
	In millions		2014			2013		2013
	Current assets
	Cash and cash equivalents		$	26		$	24	$	27
	Short-term investments			3			1		2
	Receivables			34			36		35
	Inventories			9			9		9
	Other			2			1		2
	Total current assets			74			71		75
	Long-term assets and other deferred debits
	Property, plant and equipment, net			123			124		127
	Goodwill			42			61		61
	Intangible assets			19			19		20
	Other			6			8		8
	Total long-term assets and other deferred debits			190			212		216
	Total assets held for sale		$	264		$	283	$	291
	Current liabilities
	Other accounts payable - trade		$	9		$	11	$	8
	Accrued expenses			4			7		4
	Other			23			22		22
	Total current liabilities			36			40		34
	Total liabilities held for sale		$	36		$	40	$	34
	The financial results of these businesses are reflected as discontinued operations, and all prior periods presented have been recast to reflect the discontinued operations. The components of discontinued operations recorded on the unaudited Condensed Consolidated Statements of Income are as follows:
			Three months ended
			March 31,
	In millions		2014			2013
	Operating revenues		$	89		$	87
	Operating expenses
	Cost of goods sold			54			53
	Operation and maintenance			28			26
	Depreciation and amortization			5			4
	Taxes other than income taxes			1			3
	Loss on sale and goodwill impairment (1)			19			-
	Total operating expenses			107			86
	Operating (loss) income			(18	)		1
	(Loss) income before income taxes			(18	)		1
	Income tax expense (2)			(32	)		-
	(Loss) Income from discontinued operations, net of tax		$	(50	)	$	1
	-1	Relates to $19 million of goodwill attributable to Tropical Shipping that was impaired as of March 31, 2014, based on the negotiated sales price.
	-2	Includes $31 million that was recorded in the first quarter of 2014 related to the cumulative foreign earnings for which no tax liabilities had been previously recorded.

Note_13_Revision_to_Prior_Peri

Note 13 - Revision to Prior Period Financial Statements	3 Months Ended
	Mar. 31, 2014
Accounting Changes and Error Corrections [Abstract]	'
Accounting Changes and Error Corrections [Text Block]	'
	Note 13 - Revision to Prior Period Financial Statements
	In October 2014, we identified an accounting issue related to our revenue recognition for certain of our regulatory infrastructure programs. Historically, our regulatory accounting models used to record revenues under these programs did not differentiate between allowable costs based on what the regulator has approved compared to an incurred cost that would otherwise be charged to expense under the accounting literature. Specifically, Accounting Standards Codification (ASC) 980 - Regulated Operations prohibits capitalizing allowed, but not incurred, costs such as shareholder return, even if allowed by a respective state regulatory body. Shareholder returns and other allowed, but not incurred, costs can generally only be recognized in earnings when they are collected through rates. This change is only applicable to our distribution operations segment and primarily affects our operating revenues, operation and maintenance expense, depreciation and amortization, interest expense and income tax expense amounts.
	The adjustments impacted each year since 1998.The cumulative decrease to January 1, 2013 retained earnings as a result of the adjustment was $45 million. The cumulative decrease through March 31, 2014 results in a decrease of $87 million to regulatory assets and $14 million to plant, property, and equipment. This adjustment resulted in a decrease to net income of $5 million and $4 million for the three months ended March 31, 2014 and 2013, respectively. These amounts will be recognized in future periods, when collected through rates from customers.
	Additionally, we recorded other adjustments that we identified for prior periods that were included for completeness. The most significant of these includes the intangible asset amortization. We have determined that our use of the straight-line method of amortizing our customer relationships and trade names was not applied consistent with the requirements of ASC 350 Intangibles-Goodwill and Other (ASC 350). ASC 350 requires that an intangible asset be amortized over its useful life in a manner to reflect the pattern in which the economic benefits of the intangible assets are consumed. We have determined that we should be utilizing the undiscounted cash flows as a basis to amortize these assets. The impact for this adjustment was an increase to depreciation and amortization expense of $1 million each for the three months ended March 31, 2014 and 2013. These amounts were generally offset within our unaudited Condensed Consolidated Statements of Income by the previously discussed adjustments related to our regulatory infrastructure programs for the deferral of depreciation expenses. Additionally, these adjustments resulted in a decrease to intangible assets, net of $11 million and $5 million as of March 31, 2014 and 2013, respectively. Other previously identified immaterial uncorrected amounts are reflected in the revised amounts.
	We assessed the materiality of these issues on our prior period financial statements and concluded they were not material to any prior annual or interim periods; however, the cumulative impact would have been material to the interim period ended September 30, 2014, if adjusted in 2014. As a result, in accordance with accounting standards, we revised our prior period financial statements as described below to correct for these adjustments. The revision had no effect on reported cash flows. The following tables present the effects of the revisions to our unaudited Condensed Consolidated Statements of Income, unaudited Condensed Consolidated Statements of Financial Position and unaudited Condensed Consolidated Statements of Cash Flows for the following interim periods:
			For the three months ended
			31-Mar-14									31-Mar-13
	In millions, except per share amounts		As filed (1)			Adjustment			Revised			As filed (1)			Adjustment			Revised
	Operating revenues		$	2,474		$	(12	)	$	2,462		$	1,622		$	(10	)	$	1,612
	Operating expenses
	Cost of goods sold			1,400			-			1,400			920			-			920
	Operation and maintenance			289			-			289			232			(1	)		231
	Depreciation and amortization			93			-			93			102			-			102
	Taxes other than income taxes			88			-			88			70			(1	)		69
	Total operating expenses			1,870			-			1,870			1,324			(2	)		1,322
	Operating income			604			(12	)		592			298			(8	)		290
	Other income			3			-			3			5			-			5
	Interest expense, net			(48	)		2			(46	)		(46	)		1			(45	)
	Income before income taxes			559			(10	)		549			257			(7	)		250
	Income tax expense			207			(4	)		203			94			(3	)		91
	Income from continuing operations			352			(6	)		346			163			(4	)		159
	(Loss) income from discontinued operations			(50	)		-			(50	)		1			-			1
	Net income			302			(6	)		296			164			(4	)		160
	Less net income attributable to the noncontrolling interest			12			-			12			10			-			10
	Net income attributable to AGL Resources Inc.		$	290		$	(6	)	$	284		$	154		$	(4	)	$	150
	Per common share information
	Basic earnings (loss) per common share (2)
	Continuing operations		$	2.87		$	(0.05	)	$	2.82		$	1.3		$	(0.03	)	$	1.27
	Discontinued operations			(0.43	)		-			(0.43	)		0.01			-			0.01
	Basic earnings per common share attributable to AGL Resources Inc. common shareholders		$	2.44		$	(0.05	)	$	2.39		$	1.31		$	(0.03	)	$	1.28
	Diluted earnings (loss) per common share (2)
	Continuing operations		$	2.87		$	(0.06	)	$	2.81		$	1.3		$	(0.04	)	$	1.26
	Discontinued operations			(0.43	)		-			(0.43	)		0.01			-			0.01
	Diluted earnings per common share attributable to AGL Resources Inc. common shareholders		$	2.44		$	(0.06	)	$	2.38		$	1.31		$	(0.04	)	$	1.27
		-1	Reflects the reclassification of the Tropical Shipping amounts as discontinued operations.
		-2	Excludes net income attributable to the noncontrolling interest.
	26
			As of March 31, 2014						As of March 31, 2013
	In millions		As filed (1)			Revised			As filed (1)			Revised
	Current assets
	Regulatory assets		$	297		$	250		$	119		$	72
	Other			127			127			95			93
	Total current assets			3,637			3,589			2,577			2,530
	Long-term assets and other deferred debits
	Property, plant and equipment			11,068			11,054			10,463			10,450
	Less accumulated depreciation			2,368			2,367			2,181			2,181
	Property, plant and equipment, net			8,700			8,687			8,282			8,269
	Regulatory assets			736			696			878			868
	Intangible assets			151			140			136			131
	Other			319			314			245			231
	Total long-term assets and other deferred debits			11,739			11,675			11,363			11,332
	Total assets		$	15,376		$	15,264		$	13,940		$	13,862
	Current liabilities
	Accrued expenses		$	390		$	385		$	162		$	161
	Total current liabilities			3,753			3,754			3,060			3,059
	Long-term liabilities and other deferred credits
	Accumulated deferred income taxes			1,699			1,655			1,568			1,539
	Total long-term liabilities and other deferred credits			7,711			7,667			7,339			7,310
	Total liabilities and other deferred credits		$	11,465		$	11,421		$	10,399		$	10,369
	Equity
	Additional paid-in capital		$	2,059		$	2,060		$	2,019		$	2,020
	Retained earnings			1,358			1,289			1,134			1,085
	Total equity			3,911			3,843			3,541			3,493
Total liabilities and equity		$	15,376		$	15,264		$	13,940		$	13,862
	-1	Reflects the reclassification of the Tropical Shipping amounts as held for sale.
		For the three months ended									For the three months ended
		31-Mar-14									31-Mar-13
In millions		As filed (1)			Adjustment			Revised			As filed (1)			Adjustment			Revised
Cash flows from operating activities
Net income		$	302		$	(6	)	$	296		$	164		$	(4	)	$	160
Adjustments to reconcile net income to net cash flow provided by operating activities
Depreciation and amortization			93			-			93			102			-			102
Deferred income taxes			42			(34	)		8			(24	)		(1	)		(25	)
Changes to certain assets and liabilities
Other, net			23			40			63			28			5			33
Net cash flow provided by operating activities		$	853			-		$	853		$	850			-		$	850
	-1	Reflects the reclassification of the Tropical Shipping amounts as discontinued operations.
Revision to Previously Reported Intangible Assets DisclosuresAs discussed above, the adjustment of our intangible asset amortization affects our customer relationships and trade names. The revisions to our previously reported intangible assets and accumulated amortization in our Original Filing within the unaudited Condensed Consolidated Statements of Financial Position are presented in the following table.
		31-Mar-14									31-Mar-13
In millions		Gross			Accumulated			Net			Gross			Accumulated			Net
					amortization									amortization
Customer relationships
Retail operations as reported		$	130		$	(18	)	$	112		$	99		$	(7	)	$	92
Adjustments			-			(12	)		(12	)		-			(6	)		(6	)
Revised total		$	130		$	(30	)	$	100		$	99		$	(13	)	$	86
Trade names
Retail operations as reported		$	45		$	(6	)	$	39		$	46		$	(3	)	$	43
Adjustments			-			1			1			1			1			2
Revised total		$	45		$	(5	)	$	40		$	47		$	(2	)	$	45

Note_14_Subsequent_Events

Note 14 - Subsequent Events	3 Months Ended
	Mar. 31, 2014
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	Note 14 - Subsequent Events
	Dalton Lateral Pipeline On April 11, 2014 we entered into two arrangements associated with the Dalton Lateral pipeline. The first was a construction and ownership agreement through which we will have a 50% undivided ownership interest in the 106 mile Dalton Lateral pipeline that will be constructed in Georgia and serve as an extension of the Transco natural gas pipeline system into northwest Georgia. Our 50% undivided ownership interest is expected to cost approximately $210 million. We also entered into an agreement to lease our 50% undivided ownership in the Dalton Lateral pipeline once it is placed in-service. The annual lease payments to be received are $26 million for an initial term of 25 years. The lessee will be responsible for maintaining the pipeline during the lease term and for providing service to transportation customers under its FERC regulated tariff. Engineering design work has commenced and construction is expected to begin in the second quarter of 2016 with a targeted completion date in the second quarter of 2017. On April 14, 2014, Atlanta Gas Light entered into an agreement with the lessee to acquire firm transportation capacity of 240,000 dekatherms per day associated with the Dalton Lateral pipeline. This capacity will be allocated to the Marketers and will further enhance system reliability as well as provide access to a more diverse supply of natural gas.

Accounting_Policies_by_Policy_

Accounting Policies, by Policy (Policies)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Use of Estimates, Policy [Policy Text Block]	'
	Use of Accounting Estimates
	The preparation of our financial statements in conformity with GAAP requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and the related disclosures. Our estimates are based on historical experience and various other assumptions that we believe to be reasonable under the circumstances. Our estimates may involve complex situations requiring a high degree of judgment either in the application and interpretation of existing literature or in the development of estimates that impact our financial statements. The most significant estimates relate to our rate-regulated subsidiaries, uncollectible accounts and other allowances for contingent losses, goodwill and other intangible assets, retirement plan benefit obligations, derivative and hedging activities and provisions for income taxes. We evaluate our estimates on an ongoing basis and our actual results could differ from our estimates.
Cash and Cash Equivalents, Policy [Policy Text Block]	'
	Cash and Cash Equivalents
	Our cash and cash equivalents primarily consist of cash on deposit, money market accounts and certificates of deposit held by domestic subsidiaries with original maturities of three months or less. At March 31, 2014 and 2013, and December 31, 2013, there were $26 million, $27 million and $24 million, respectively, of cash and cash equivalents held by Tropical Shipping that were excluded from cash and cash equivalents within our unaudited Condensed Consolidated Statements of Financial Position and included in assets held for sale. For more information on the sale of Tropical Shipping, see Note 12.
Energy Marketing Receivables And Payables [Policy Text Block]	'
	Energy Marketing Receivables and Payables
	Our wholesale services segment provides services to retail and wholesale marketers and utility and industrial customers. These customers, also known as counterparties, utilize netting agreements that enable our wholesale services segment to net receivables and payables by counterparty upon settlement. Wholesale services also nets across product lines and against cash collateral, provided the master netting and cash collateral agreements include such provisions. While the amounts due from, or owed to, wholesale services’ counterparties are settled net, they are recorded on a gross basis in our unaudited Condensed Consolidated Statements of Financial Position as energy marketing receivables and energy marketing payables.
	Our wholesale services segment has trade and credit contracts that contain minimum credit rating requirements. These credit rating requirements typically give counterparties the right to suspend or terminate credit if our credit ratings are downgraded to non-investment grade status. Under such circumstances, wholesale services would need to post collateral to continue transacting business with some of its counterparties. To date, our credit ratings have exceeded the minimum requirements. As of March 31, 2014 and 2013, and December 31, 2013, the collateral that wholesale services would have been required to post if our credit ratings had been downgraded to non-investment grade status would not have had a material impact to our consolidated results of operations, cash flows or financial condition. If such collateral were not posted, wholesale services’ ability to continue transacting business with these counterparties would be negatively impacted.
Inventory, Policy [Policy Text Block]	'
	Inventories
	For our regulated utilities, except Nicor Gas, our natural gas inventories and the inventories we hold for Marketers in Georgia are carried at cost on a WACOG basis. In Georgia’s competitive environment, Marketers sell natural gas to firm end-use customers at market-based prices. Part of the unbundling process, which resulted from deregulation and provides this competitive environment, is the assignment to Marketers of certain pipeline services that Atlanta Gas Light has under contract. On a monthly basis, Atlanta Gas Light assigns the majority of the pipeline storage services that it has under contract to Marketers, along with a corresponding amount of inventory. Atlanta Gas Light also retains and manages a portion of its pipeline storage assets and related natural gas inventories for system balancing and to serve system demand. See Note 10 for information regarding a regulatory filing by Atlanta Gas Light related to natural gas inventory.
	Nicor Gas’ inventory is carried at cost on a LIFO basis. Inventory decrements occurring during interim periods that are expected to be restored prior to year end are charged to cost of goods sold at the estimated annual replacement cost, and the difference between this cost and the actual liquidated LIFO layer cost is recorded as a temporary LIFO inventory liquidation. Any temporary LIFO liquidation is included as a current liability in our unaudited Condensed Consolidated Statements of Financial Position. Interim inventory decrements that are not expected to be restored prior to year end are charged to cost of goods sold at the actual LIFO cost of the layers liquidated. The inventory decrement as of March 31, 2014 is expected to be restored prior to year end. The inventory decrement as of March 31, 2013 was restored prior to December 31, 2013.
	Our retail operations, wholesale services and midstream operations segments carry inventory at the lower of cost or market value, where cost is determined on a WACOG basis. For these segments, we evaluate the weighted average cost of their natural gas inventories against market prices to determine whether any declines in market prices below the WACOG are other than temporary. For any declines considered to be other than temporary, we record adjustments to reduce the weighted average cost of the natural gas inventory to market value. For the three months ended March 31, 2014, wholesale services recorded a $2 million LOCOM adjustment to reduce the value of our inventories to market value. We recorded no LOCOM adjustment for the three months ended March 31, 2013.
Fair Value Measurement, Policy [Policy Text Block]	'
	Fair Value Measurements
	We have financial and nonfinancial assets and liabilities subject to fair value measurement. The financial assets and liabilities measured and carried at fair value include cash and cash equivalents, and derivative assets and liabilities. The carrying values of receivables, short and long-term investments, accounts payable, short-term debt, other current assets and liabilities, and accrued interest approximate fair value. Our nonfinancial assets and liabilities include pension and other retirement benefits, which are presented in Note 4 to our Consolidated Financial Statements and in related notes included in Item 8 of our 2013 Form 10-K/A.
	As defined in the authoritative guidance related to fair value measurements and disclosures, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We utilize market data or assumptions that market participants would use in valuing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. We primarily apply the market approach for recurring fair value measurements to utilize the best available information. Accordingly, we use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. We classify fair value balances based on the observance of those inputs in accordance with the fair value hierarchy.
Derivatives, Policy [Policy Text Block]	'
	Derivative Instruments
	The fair value of the natural gas and weather derivative instruments that we use to manage exposures arising from changing natural gas prices and weather risk reflects the estimated amounts that we would receive or pay to terminate or close the contracts at the reporting date, taking into account the current unrealized gains or losses on open contracts. We use external market quotes and indices to value substantially all of our derivative instruments. See Note 4 and Note 5 for additional derivative disclosures.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	'
	Goodwill
	During the first quarter of 2014, we completed an engineering study at our storage and fuels reporting unit within midstream operations, which indicated a reduced forecast of working gas capacity from what was projected when our 2013 annual goodwill impairment analysis was performed during the fourth quarter of 2013. Given that the 2013 annual goodwill impairment test indicated that the estimated fair value of this reporting unit exceeded its carrying amount by less than 5%, we considered this reduced storage capacity as an indicator of potential impairment and, accordingly, conducted an interim goodwill impairment analysis during the first quarter of 2014.
	The estimated fair value of this reporting unit was determined utilizing the income approach, which estimated the fair value based upon the present value of estimated future cash flows. The forecasts used in the income approach, which were updated during the first quarter of 2014 to reflect the contracting activity that occurred during the quarter, assume discrete period revenue growth through fiscal 2022 to reflect the recovery of subscription rates, stabilization of earnings and establishment of a reasonable base year that was used to estimate the terminal value. Consistent with our 2013 annual goodwill impairment testing, we assumed a long-term earnings growth rate in the terminal year of 2.5%, which we believe is appropriate given the current economic and industry specific expectations. As of the valuation date, we utilized a discount rate of 7.0%, which we believe is appropriate as it reflects the relative risk and the time value of money, and is consistent with the peer group of this reporting unit as well as the discount rates that were utilized in our 2013 annual goodwill impairment tests.
	The cash flow forecasts for this reporting unit assumed earnings growth over the next eight years. Should this growth not occur, this reporting unit may fail step one during a future goodwill impairment test. Along with any reductions to our cash flow forecasts, changes in other assumptions used in our impairment analysis may require us to proceed to step two of the goodwill impairment test in a future period.
	Our interim goodwill impairment test indicated that the estimated fair value of this reporting unit continues to exceed its carrying amount with a cushion of less than 10%. Continued declines in capacity or subscription rates, a sustained period at the current subscription rates or other changes to the assumptions and factors used in this analysis may result in a future failure of step one of the goodwill impairment test. The risk of impairment of the underlying long-lived assets is not estimated to be significant as the assets have long remaining useful lives and authoritative guidance requires such assets to be tested for impairment on the basis of undiscounted cash flows over their remaining useful lives. We will continue to monitor this reporting unit for potential impairment. Our goodwill balances by segment as of March 31, 2014, and December 31, 2013, and changes in the amount of goodwill for the three months ended March 31, 2013, are provided in the following table.
	In millions		Distribution Operations			Retail			Midstream Operations		Consolidated
						Operations
	December 31, 2012 (1)		$	1,640		$	122		$	14	$	1,776
	2013 acquisitions			-			46			-		46
	March 31, 2013 (1)		$	1,640		$	168		$	14	$	1,822
	December 31, 2013 (1)		$	1,640		$	173		$	14	$	1,827
	March 31, 2014 (1)		$	1,640		$	173		$	14	$	1,827
	-1	Excludes goodwill at Tropical Shipping which is classified as held for sale. See Note 12 for additional information.
Other Income [Policy Text Block]	'
	Other Income
	Our other income is detailed in the following table. For more information on our equity investment income, see Note 9.
			Three months ended
			March 31,
	In millions		2014			2013
	Equity investment income		$	3		$	3
	AFUDC - equity			1			3
	Other, net			(1	)		(1	)
	Total other income		$	3		$	5
Earnings Per Share, Policy [Policy Text Block]	'
	Earnings Per Common Share
	We compute basic earnings per common share attributable to AGL Resources Inc. common shareholders by dividing our net income attributable to AGL Resources Inc. by the daily weighted average number of common shares outstanding. Diluted earnings per common share attributable to AGL Resources Inc. common shareholders reflect the potential reduction in earnings per common share attributable to AGL Resources Inc. common shareholders that occurs when potentially dilutive common shares are added to common shares outstanding.
	We derive our potentially dilutive common shares by calculating the number of shares issuable under restricted stock, restricted stock units and stock options. The vesting of certain shares of the restricted stock and restricted stock units depends on the satisfaction of defined performance and/or time based criteria. The future issuance of shares underlying the outstanding stock options depends on whether the market price of the common shares underlying the options exceeds the respective exercise prices of the stock options.
	The following table shows the calculation of our diluted shares attributable to AGL Resources Inc. common shareholders for the periods presented, if performance units currently earned under the plan ultimately vest and if stock options currently exercisable at prices below the average market prices are exercised.
			Three months ended March 31,
	In millions (except per share amounts)		2014 (1)			2013 (1)
	Income from continuing operations (2)		$	334		$	149
	(Loss) income from discontinued operations, net of tax (3)			(50	)		1
	Net income attributable to AGL Resources Inc.		$	284		$	150
	Denominator:
	Basic weighted average number of shares outstanding (4)			118.5			117.4
	Effect of dilutive securities			0.4			0.3
	Diluted weighted average number of shares outstanding			118.9			117.7
	Basic earnings (loss) per common share
	From continuing operations		$	2.82		$	1.27
	From discontinued operations			(0.43	)		0.01
	Basic earnings per common share attributable to AGL Resources Inc. common shareholders		$	2.39		$	1.28
	Diluted earnings (loss) per common share
	From continuing operations		$	2.81		$	1.26
	From discontinued operations			(0.43	)		0.01
	Diluted earnings per common share attributable to AGL Resources Inc. common shareholders		$	2.38		$	1.27
		-1	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
		-2	Excludes net income attributable to the noncontrolling interest.
		-3	For additional information on our discontinued operations, see Note 12.
		-4	Daily weighted average shares outstanding.
New Accounting Pronouncements, Policy [Policy Text Block]	'
	Accounting Developments
	On April 10, 2014, the FASB issued authoritative guidance related to reporting discontinued operations. The guidance generally raises the threshold for disposals to qualify as discontinued operations and requires new disclosures of both discontinued operations and certain other material disposals that do not meet the definition of a discontinued operation. The guidance will be effective for us prospectively beginning January 1, 2015 and it is not expected to have a material impact on our consolidated financial statements nor will it have an impact on our accounting for the sale of Tropical Shipping. While permitted, we do not intend to adopt the guidance early.

Note_2_Significant_Accounting_1

Note 2 - Significant Accounting Policies and Methods of Application (Tables)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Schedule of Goodwill [Table Text Block]	'
	In millions	Distribution Operations			Retail			Midstream Operations		Consolidated
					Operations
	December 31, 2012 (1)	$	1,640		$	122		$	14	$	1,776
	2013 acquisitions		-			46			-		46
	March 31, 2013 (1)	$	1,640		$	168		$	14	$	1,822
	December 31, 2013 (1)	$	1,640		$	173		$	14	$	1,827
	March 31, 2014 (1)	$	1,640		$	173		$	14	$	1,827
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	'
		Three months ended
		March 31,
	In millions	2014			2013
	Equity investment income	$	3		$	3
	AFUDC - equity		1			3
	Other, net		(1	)		(1	)
	Total other income	$	3		$	5
Schedule of Weighted Average Number of Shares [Table Text Block]	'
		Three months ended March 31,
	In millions (except per share amounts)	2014 (1)			2013 (1)
	Income from continuing operations (2)	$	334		$	149
	(Loss) income from discontinued operations, net of tax (3)		(50	)		1
	Net income attributable to AGL Resources Inc.	$	284		$	150
	Denominator:
	Basic weighted average number of shares outstanding (4)		118.5			117.4
	Effect of dilutive securities		0.4			0.3
	Diluted weighted average number of shares outstanding		118.9			117.7
	Basic earnings (loss) per common share
	From continuing operations	$	2.82		$	1.27
	From discontinued operations		(0.43	)		0.01
	Basic earnings per common share attributable to AGL Resources Inc. common shareholders	$	2.39		$	1.28
	Diluted earnings (loss) per common share
	From continuing operations	$	2.81		$	1.26
	From discontinued operations		(0.43	)		0.01
	Diluted earnings per common share attributable to AGL Resources Inc. common shareholders	$	2.38		$	1.27

Note_3_Regulated_Operations_Ta

Note 3 - Regulated Operations (Tables)	3 Months Ended
	Mar. 31, 2014
Note 3 - Regulated Operations (Tables) [Line Items]	'
Schedule of Regulatory Assets [Table Text Block]	'
	In millions	March 31, 2014 (1)				December 31, 2013 (1)				March 31, 2013 (1)
	Regulatory assets
	Deferred natural gas costs	$	161			$	1			$	-
	Recoverable ERC		38				45				28
	Recoverable pension and retiree welfare benefit costs		9				9				19
	Other		42				59				25
	Total regulatory assets - current		250				114				72
	Recoverable ERC		419				433				415
	Recoverable pension and retiree welfare benefit costs		97				99				192
	Recoverable regulatory infrastructure program costs		57				55				125
	Long-term debt fair value adjustment		80				82				88
	Other		43				36				48
	Total regulatory assets - long-term		696				705				868
	Total regulatory assets	$	946			$	819			$	940
	Regulatory liabilities
	Bad debt over collection	$	41			$	41			$	39
	Accumulated removal costs		27				27				17
	Accrued natural gas costs		24				92				133
	Deferred seasonal rates		20				-				20
	Other		49				23				29
	Total regulatory liabilities - current		161				183				238
	Accumulated removal costs		1,456				1,445				1,413
	Regulatory income tax liability		27				27				26
	Unamortized investment tax credit		25				26				28
	Bad debt over collection		14				17				20
	Other		28				3				11
	Total regulatory liabilities - long-term		1,550				1,518				1,498
	Total regulatory liabilities	$	1,711			$	1,701			$	1,736
Schedule of Net Regulatory Assets [Table Text Block]	'
	In millions	31-Mar-14				31-Mar-13				Change
	Deferred natural gas costs	$	161			$	-			$	161
	Accrued natural gas costs		(24	)			(133	)			109
	Total (1)	$	137			$	(133	)		$	270
Environmental Exit Costs by Cost [Table Text Block]	'
	In millions	Probabilistic model cost estimates		Engineering estimates				Amount recorded				Expected costs over next 12 months
	Illinois	$211 - $461		$	42			$	246			$	39
	New Jersey	139 - 233			6				144				25
	Georgia and Florida	28 - 112			8				39				10
	North Carolina	n/a			11				11				8
	Total	$378 - $806		$	67			$	440			$	82
Regulatory Assett Off Balance Sheet [Member]	'
Note 3 - Regulated Operations (Tables) [Line Items]	'
Schedule of Regulatory Assets [Table Text Block]	'
	In millions
	31-Mar-14	$	102
	31-Dec-13	$	93
	31-Mar-13	$	71

Note_4_Fair_Value_Measurements1

Note 4 - Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Note 4 - Fair Value Measurements (Tables) [Line Items]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	'
	In millions	31-Mar-14		31-Dec-13			31-Mar-13
	Long-term debt carrying amount	$	3,810	$	3,813		$	3,550
	Long-term debt fair value (1)		4,095		3,956			4,006
Natural Gas and Interest Rate Derivatives [Member]	'
Note 4 - Fair Value Measurements (Tables) [Line Items]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	'
		31-Mar-14					31-Dec-13					31-Mar-13
	In millions	Assets (1)		Liabilities			Assets (1)		Liabilities			Assets (1)		Liabilities
	Natural gas derivatives
	Quoted prices in active markets (Level 1)	$	18	$	(38	)	$	6	$	(79	)	$	14	$	(38	)
	Significant other observable inputs (Level 2)		50		(75	)		67		(79	)		49		(23	)
	Netting of cash collateral		69		31			43		78			40		37
	Total carrying value (2) (3)	$	137	$	(82	)	$	116	$	(80	)	$	103	$	(24	)
	Interest rate derivatives
	Significant other observable inputs (Level 2)	$	-	$	-		$	-	$	-		$	6	$	-

Note_5_Derivative_Instruments_

Note 5 - Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	'
	In Bcf (1)		March 31, 2014 (2)				31-Dec-13				31-Mar-13
	Hedge designation
	Cash flow hedges			6				6				6
	Not designated as hedges			277				183				304
	Total hedges			283				189				310
	Hedge position
	Short position			(2,491	)			(2,622	)			(1,902	)
	Long position			2,774				2,811				2,212
	Net long position			283				189				310
Loss Recognized In Income [Table Text Block]	'
			Three months ended March 31,
	In millions		2014				2013
	Nicor Gas		$	2			$	(1	)
	Elizabethtown Gas			3				(3	)
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	'
				March 31,								31-Dec-13						March 31,
				2014														2013
	In millions	Classification		Assets				Liabilities				Assets			Liabilities			Assets			Liabilities
	Designated as cash flow hedges and fair value hedges
	Natural gas contracts	Current		$	2			$	-			$	3		$	(1	)	$	3		$	(1	)
	Interest rate swap agreements	Current			-				-				-			-			5			-
	Total				2				-				3			(1	)		8			(1	)
	Not designated as cash flow hedges
	Natural gas contracts	Current			675				(703	)			691			(761	)		332			(327	)
	Natural gas contracts	Long-term			80				(98	)			206			(220	)		46			(48	)
	Total				755				(801	)			897			(981	)		378			(375	)
	Gross amount of recognized assets and liabilities (1)				757				(801	)			900			(982	)		386			(376	)
	Gross amounts offset in our unaudited Condensed Consolidated Statements of Financial Position (2)				(619	)			719				(781	)		902			(275	)		352
	Net amounts of assets and liabilities presented in our unaudited Condensed Consolidated Statements of Financial Position (3)			$	138			$	(82	)		$	119		$	(80	)	$	111		$	(24	)
Schedule of Derivative Instruments [Table Text Block]	'
			Three months ended March 31,
	In millions		2014				2013
	Designated as cash flow hedges
	Natural gas contracts - net gain reclassified from OCI to cost of goods sold		$	3			$	-
	Natural gas contracts - net gain reclassified from OCI to operation and maintenance expense			1				-
	Interest rate swaps - loss reclassified from OCI to interest expense			-				(3	)
	Income tax benefit			-				1
	Net of tax			4				(2	)
	Not designated as hedges (1)
	Natural gas contracts - net fair value adjustments recorded in operating revenues			(30	)			(24	)
	Natural gas contracts - net fair value adjustments recorded in cost of goods sold (2)			2				-
	Income tax benefit			11				8
	Net of tax			(17	)			(16	)
	Total losses on derivative instruments, net of tax		$	(13	)		$	(18	)

Note_6_Employee_Benefit_Plans_

Note 6 - Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Schedule of Net Benefit Costs [Table Text Block]	'
		Three months ended March 31,
	In millions	2014			2013
	Service cost	$	6		$	8
	Interest cost		12			10
	Expected return on plan assets		(16	)		(16	)
	Recognized actuarial loss		5			8
	Net periodic pension benefit cost	$	7		$	10
		Three months ended March 31,
	In millions	2014			2013
	Service cost	$	1		$	1
	Interest cost		4			3
	Expected return on plan assets		(2	)		(1	)
	Net amortization of prior service cost		(1	)		(1	)
	Recognized actuarial loss		1			2
	Net periodic welfare benefit cost	$	3		$	4

Note_7_Debt_and_Credit_Facilit1

Note 7 - Debt and Credit Facilities (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Debt [Table Text Block]	'
					31-Mar-14								31-Mar-13
	Dollars in millions	Year(s) due			Weighted average			Outstanding			Outstanding at December 31, 2013		Weighted average			Outstanding
					interest rate (1)								interest rate (1)
	Short-term debt
	Commercial paper - AGL Capital (2)	2014				0.3	%	$	440		$	857		0.5	%	$	868
	Commercial paper - Nicor Gas (2)	2014				0.2			301			314		0.4			-
	Total short-term debt					0.3			741			1,171		0.5			868
	Current portion of long-term debt and capital leases
	Current portion of long-term debt	2015				5			200			-		4.5			225
	Current portion of capital leases	n/a				-			-			-		5			1
	Total current portion of long-term debt and capital leases					5	%	$	200		$	-		4.5	%	$	226
	Long-term debt - excluding current portion
	Senior notes	2016-2043				5	%	$	2,625		$	2,825		5.1	%	$	2,325
	First mortgage bonds	2016-2038				5.6			500			500		5.6			500
	Gas facility revenue bonds	2022-2033				0.9			200			200		1.2			200
	Medium-term notes	2017-2027				7.8			181			181		7.8			181
	Total principal long-term debt					4.9	%		3,506			3,706		5	%		3,206
	Fair value adjustment of long-term debt (3)	2016-2038			n/a				88			91	n/a				100
	Unamortized debt premium, net	n/a			n/a				16			16	n/a				18
	Total non-principal long-term debt				n/a				104			107	n/a				118
	Total long-term debt							$	3,610		$	3,813				$	3,324
	Total debt							$	4,551		$	4,984				$	4,418
Schedule of Capitalization [Table Text Block]	'
		31-Mar-14			31-Dec-13			31-Mar-13
	AGL Credit Facility		54	%		57	%		55	%
	Nicor Gas Credit Facility		54	%		55	%		43	%

Note_8_Equity_Tables

Note 8 - Equity (Tables)	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	In millions (1)	Cash flow hedges			Retirement benefit plans			Total
	As of December 31, 2012	$	(3	)	$	(215	)	$	(218	)
	OCI, before reclassifications		2			-			2
	Amounts reclassified from accumulated OCI		2			3			5
	As of March 31, 2013		1			(212	)		(211	)
	As of December 31, 2013		1			(137	)		(136	)
	OCI, before reclassifications		4			-			4
	Amounts reclassified from accumulated OCI		(4	)		1			(3	)
	As of March 31, 2014	$	1		$	(136	)	$	(135	)
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	'
		Three months ended March 31,
	In millions (1)	2014			2013
	Cash flow hedges
	Natural gas contracts (2)	$	4		$	-
	Interest rate contracts (3)		-			(3	)
	Total before income tax		4			(3	)
	Income tax benefit		-			1
	Total cash flow hedges		4			(2	)
	Retirement benefit plan amortization of
	Actuarial losses (4)		(2	)		(6	)
	Prior service credits (4)		-			1
	Total before income tax		(2	)		(5	)
	Income tax benefit		1			2
	Total retirement benefit plans		(1	)		(3	)
	Total reclassification for the period	$	3		$	(5	)

Note_9_NonWholly_Owned_Entitie1

Note 9 - Non-Wholly Owned Entities (Tables)	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table Text Block]	'
		March 31, 2014 (1) (2)							December 31, 2013 (1) (2)							March 31, 2013 (1) (2)
	In millions	Consolidated		SouthStar(3)		-4%			Consolidated		SouthStar(3)		-4%			Consolidated		SouthStar(3)		-4%
	Current assets	$	3,589	$	235		7	%	$	2,895	$	264		9	%	$	2,530	$	143		6	%
	Goodwill and other intangible assets		1,967		131		7			1,972		133		7			1,953		-		-
	Long-term assets and other deferred debits		9,708		16		-			9,683		13		-			9,379		10		-
	Total assets	$	15,264	$	382		3	%	$	14,550	$	410		3	%	$	13,862	$	153		1	%
	Current liabilities	$	3,754	$	106		3	%	$	3,118	$	95		3	%	$	3,059	$	51		2	%
	Long-term liabilities and other deferred credits		7,667		-		-			7,819		-		-			7,310		-		-
	Total Liabilities		11,421		106		1			10,937		95		1			10,369		51		-
	Equity		3,843		276		7			3,613		315		9			3,493		102		3
	Total liabilities and equity	$	15,264	$	382		3	%	$	14,550	$	410		3	%	$	13,862	$	153		1	%
Schedule of Variable Interest Entities [Table Text Block]	'
		Three months ended March 31,
	In millions	2014 (1)		2013 (1)
	Operating revenues	$	374	$	250
	Operating expenses
	Cost of goods sold		270		164
	Operation and maintenance		23		18
	Depreciation and amortization		3		1
	Total operating expenses		296		183
	Operating income	$	78	$	67
Equity Method Investments [Table Text Block]	'
	In millions	2014		2013
	Triton	$	67	$	72
	Horizon Pipeline		15		16
	Other (1)		1		9
	Total	$	83	$	97
	In millions	2014		2013
	Triton	$	2	$	2
	Horizon Pipeline		1		1
	Total	$	3	$	3

Note_11_Segment_Information_Ta

Note 11 - Segment Information (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Schedule Of Segment Reporting Information By Segment Total Assets Goodwill [Table Text Block]	'
	In millions	Identifiable and			Goodwill
		total assets (1) (2)
	Distribution operations	$	11,634		$	1,640
	Retail operations		685			173
	Wholesale services		1,163			-
	Midstream operations		713			14
	Other (3)		10,160			-
	Intercompany eliminations		(10,088	)		-
	Consolidated	$	14,267		$	1,827
Schedule of Segment Reporting Information, by Segment [Table Text Block]	'
	In millions	Distributionoperations			Retail operations		Wholesale services (2)		Midstream operations			Other (4)			Intercompany eliminations			Consolidated
	Operating revenues from external parties	$	1,726		$	406	$	331	$	44		$	3		$	(48	)	$	2,462
	Intercompany revenues		75			-		-		-			-			(75	)		-
	Total operating revenues		1,801			406		331		44			3			(123	)		2,462
	Operating expenses
	Cost of goods sold		1,202			280		3		36			-			(121	)		1,400
	Operation and maintenance		211			37		36		6			1			(2	)		289
	Depreciation and amortization		78			8		-		5			2			-			93
	Taxes other than income taxes		82			1		1		1			3			-			88
	Total operating expenses		1,573			326		40		48			6			(123	)		1,870
	Operating income (loss)		228			80		291		(4	)		(3	)		-			592
	Other income		1			-		-		1			1			-			3
	EBIT	$	229		$	80	$	291	$	(3	)	$	(2	)	$	-		$	595
	Identifiable and total assets (3)	$	11,823		$	738	$	1,782	$	698		$	9,844		$	(9,885	)	$	15,000
	Capital expenditures	$	150		$	3	$	1	$	-		$	7		$	-		$	161
	In millions	Distributionoperations			Retail operations		Wholesale services (2)		Midstream operations			Other (4)			Intercompany eliminations			Consolidated
	Operating revenues from external parties	$	1,255		$	302	$	39	$	24		$	1		$	(9	)	$	1,612
	Intercompany revenues		55			-		-		-			-			(55	)		-
	Total operating revenues		1,310			302		39		24			1			(64	)		1,612
	Operating expenses
	Cost of goods sold		765			195		10		12			-			(62	)		920
	Operation and maintenance		185			31		13		6			(2	)		(2	)		231
	Depreciation and amortization		88			6		-		4			4			-			102
	Taxes other than income taxes		64			1		1		1			2			-			69
	Total operating expenses		1,102			233		24		23			4			(64	)		1,322
	Operating income (loss)		208			69		15		1			(3	)		-			290
	Other income		3			-		-		1			1			-			5
	EBIT	$	211		$	69	$	15	$	2		$	(2	)	$	-		$	295
	Identifiable and total assets (3)	$	11,188		$	663	$	1,005	$	714		$	9,732		$	(9,731	)	$	13,571
	Capital expenditures	$	137		$	1	$	-	$	4		$	5		$	-		$	147
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	'
	In millions	Third party gross revenues			Intercompany revenues		Total gross revenues		Less gross			Operating revenues
									gas costs
	Three months ending March 31, 2014	$	4,049		$	298	$	4,347	$	4,016		$	331
	Three months ending March 31, 2013		2,094			140		2,234		2,195			39

Note_12_Discontinued_Operation1

Note 12 - Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2014
Balance Sheet [Member]	'
Note 12 - Discontinued Operations (Tables) [Line Items]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
		March 31,			December 31,		March 31,
	In millions	2014			2013		2013
	Current assets
	Cash and cash equivalents	$	26		$	24	$	27
	Short-term investments		3			1		2
	Receivables		34			36		35
	Inventories		9			9		9
	Other		2			1		2
	Total current assets		74			71		75
	Long-term assets and other deferred debits
	Property, plant and equipment, net		123			124		127
	Goodwill		42			61		61
	Intangible assets		19			19		20
	Other		6			8		8
	Total long-term assets and other deferred debits		190			212		216
	Total assets held for sale	$	264		$	283	$	291
	Current liabilities
	Other accounts payable - trade	$	9		$	11	$	8
	Accrued expenses		4			7		4
	Other		23			22		22
	Total current liabilities		36			40		34
	Total liabilities held for sale	$	36		$	40	$	34
Income Statement [Member]	'
Note 12 - Discontinued Operations (Tables) [Line Items]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
		Three months ended
		March 31,
	In millions	2014			2013
	Operating revenues	$	89		$	87
	Operating expenses
	Cost of goods sold		54			53
	Operation and maintenance		28			26
	Depreciation and amortization		5			4
	Taxes other than income taxes		1			3
	Loss on sale and goodwill impairment (1)		19			-
	Total operating expenses		107			86
	Operating (loss) income		(18	)		1
	(Loss) income before income taxes		(18	)		1
	Income tax expense (2)		(32	)		-
	(Loss) Income from discontinued operations, net of tax	$	(50	)	$	1

Note_13_Revision_to_Prior_Peri1

Note 13 - Revision to Prior Period Financial Statements (Tables)	3 Months Ended
	Mar. 31, 2014
Revisions to Income Statement [Member]	'
Note 13 - Revision to Prior Period Financial Statements (Tables) [Line Items]	'
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	'
		For the three months ended
		31-Mar-14									31-Mar-13
	In millions, except per share amounts	As filed (1)			Adjustment			Revised			As filed (1)			Adjustment			Revised
	Operating revenues	$	2,474		$	(12	)	$	2,462		$	1,622		$	(10	)	$	1,612
	Operating expenses
	Cost of goods sold		1,400			-			1,400			920			-			920
	Operation and maintenance		289			-			289			232			(1	)		231
	Depreciation and amortization		93			-			93			102			-			102
	Taxes other than income taxes		88			-			88			70			(1	)		69
	Total operating expenses		1,870			-			1,870			1,324			(2	)		1,322
	Operating income		604			(12	)		592			298			(8	)		290
	Other income		3			-			3			5			-			5
	Interest expense, net		(48	)		2			(46	)		(46	)		1			(45	)
	Income before income taxes		559			(10	)		549			257			(7	)		250
	Income tax expense		207			(4	)		203			94			(3	)		91
	Income from continuing operations		352			(6	)		346			163			(4	)		159
	(Loss) income from discontinued operations		(50	)		-			(50	)		1			-			1
	Net income		302			(6	)		296			164			(4	)		160
	Less net income attributable to the noncontrolling interest		12			-			12			10			-			10
	Net income attributable to AGL Resources Inc.	$	290		$	(6	)	$	284		$	154		$	(4	)	$	150
	Per common share information
	Basic earnings (loss) per common share (2)
	Continuing operations	$	2.87		$	(0.05	)	$	2.82		$	1.3		$	(0.03	)	$	1.27
	Discontinued operations		(0.43	)		-			(0.43	)		0.01			-			0.01
	Basic earnings per common share attributable to AGL Resources Inc. common shareholders	$	2.44		$	(0.05	)	$	2.39		$	1.31		$	(0.03	)	$	1.28
	Diluted earnings (loss) per common share (2)
	Continuing operations	$	2.87		$	(0.06	)	$	2.81		$	1.3		$	(0.04	)	$	1.26
	Discontinued operations		(0.43	)		-			(0.43	)		0.01			-			0.01
	Diluted earnings per common share attributable to AGL Resources Inc. common shareholders	$	2.44		$	(0.06	)	$	2.38		$	1.31		$	(0.04	)	$	1.27
Revisions to Balance Sheets [Member]	'
Note 13 - Revision to Prior Period Financial Statements (Tables) [Line Items]	'
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	'
		As of March 31, 2014						As of March 31, 2013
	In millions	As filed (1)			Revised			As filed (1)			Revised
	Current assets
	Regulatory assets	$	297		$	250		$	119		$	72
	Other		127			127			95			93
	Total current assets		3,637			3,589			2,577			2,530
	Long-term assets and other deferred debits
	Property, plant and equipment		11,068			11,054			10,463			10,450
	Less accumulated depreciation		2,368			2,367			2,181			2,181
	Property, plant and equipment, net		8,700			8,687			8,282			8,269
	Regulatory assets		736			696			878			868
	Intangible assets		151			140			136			131
	Other		319			314			245			231
	Total long-term assets and other deferred debits		11,739			11,675			11,363			11,332
	Total assets	$	15,376		$	15,264		$	13,940		$	13,862
	Current liabilities
	Accrued expenses	$	390		$	385		$	162		$	161
	Total current liabilities		3,753			3,754			3,060			3,059
	Long-term liabilities and other deferred credits
	Accumulated deferred income taxes		1,699			1,655			1,568			1,539
	Total long-term liabilities and other deferred credits		7,711			7,667			7,339			7,310
	Total liabilities and other deferred credits	$	11,465		$	11,421		$	10,399		$	10,369
	Equity
	Additional paid-in capital	$	2,059		$	2,060		$	2,019		$	2,020
	Retained earnings		1,358			1,289			1,134			1,085
	Total equity		3,911			3,843			3,541			3,493
	Total liabilities and equity	$	15,376		$	15,264		$	13,940		$	13,862
Revisions to Statement of Cash Flows [Member]	'
Note 13 - Revision to Prior Period Financial Statements (Tables) [Line Items]	'
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	'
		For the three months ended									For the three months ended
		31-Mar-14									31-Mar-13
	In millions	As filed (1)			Adjustment			Revised			As filed (1)			Adjustment			Revised
	Cash flows from operating activities
	Net income	$	302		$	(6	)	$	296		$	164		$	(4	)	$	160
	Adjustments to reconcile net income to net cash flow provided by operating activities
	Depreciation and amortization		93			-			93			102			-			102
	Deferred income taxes		42			(34	)		8			(24	)		(1	)		(25	)
	Changes to certain assets and liabilities
	Other, net		23			40			63			28			5			33
	Net cash flow provided by operating activities	$	853			-		$	853		$	850			-		$	850
Revision to Intangible Assets [Member]	'
Note 13 - Revision to Prior Period Financial Statements (Tables) [Line Items]	'
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	'
		31-Mar-14									31-Mar-13
	In millions	Gross			Accumulated			Net			Gross			Accumulated			Net
					amortization									amortization
	Customer relationships
	Retail operations as reported	$	130		$	(18	)	$	112		$	99		$	(7	)	$	92
	Adjustments		-			(12	)		(12	)		-			(6	)		(6	)
	Revised total	$	130		$	(30	)	$	100		$	99		$	(13	)	$	86
	Trade names
	Retail operations as reported	$	45		$	(6	)	$	39		$	46		$	(3	)	$	43
	Adjustments		-			1			1			1			1			2
	Revised total	$	45		$	(5	)	$	40		$	47		$	(2	)	$	45

Note_1_Organization_and_Basis_1

Note 1 - Organization and Basis of Presentation (Details) (Incentive Compensation [Member], USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Feb. 28, 2012
Performance Shares [Member]	'
Note 1 - Organization and Basis of Presentation (Details) [Line Items]	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested	$1
Restricted Stock [Member]	'
Note 1 - Organization and Basis of Presentation (Details) [Line Items]	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	37,290

Note_2_Significant_Accounting_2

Note 2 - Significant Accounting Policies and Methods of Application (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
			Midstream Operations [Member]	Midstream Operations [Member]	Tropical Shipping [Member]	Tropical Shipping [Member]	Tropical Shipping [Member]
			Goodwill [Member]
Note 2 - Significant Accounting Policies and Methods of Application (Details) [Line Items]	'	'	'	'	'	'	'
Investments and Cash	'	'	'	'	$26,000,000	$24,000,000	$27,000,000
Inventory Write-down	$2,000,000	$0	'	'	'	'	'
Percent Goodwill Exceeds Carrying Value	'	'	'	5.00%	'	'	'
Fair Value Inputs, Long-term Revenue Growth Rate	'	'	2.50%	'	'	'	'
Fair Value Inputs, Discount Rate	'	'	7.00%	'	'	'	'

Note_2_Significant_Accounting_3

Note 2 - Significant Accounting Policies and Methods of Application (Details) - Changes in Amount of Goodwill (USD $)

3 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Distribution Operations [Member]

Distribution Operations [Member]

Distribution Operations [Member]

Distribution Operations [Member]

Retail Operations [Member]

Retail Operations [Member]

Retail Operations [Member]

Midstream Operations [Member]

Midstream Operations [Member]

Midstream Operations [Member]

Midstream Operations [Member]

Goodwill [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance

$1,776

[1]

$1,827

[1]

$1,827

[1]

$1,640

[1]

$1,640

[1]

$1,640

[1]

$1,640

[1]

$122

[1]

$173

[1]

$173

[1]

$14

[1]

$14

[1]

$14

[1]

$14

[1]

2013 acquisitions

46

'

'

'

'

'

'

46

'

'

'

'

'

'

Balance

$1,822

[1]

$1,827

[1]

$1,827

[1]

$1,640

[1]

$1,640

[1]

$1,640

[1]

$1,640

[1]

$168

[1]

$173

[1]

$173

[1]

$14

[1]

$14

[1]

$14

[1]

$14

[1]

[1]

Excludes goodwill at Tropical Shipping which is classified as held for sale. See Note 12 for additional information.

Note_2_Significant_Accounting_4

Note 2 - Significant Accounting Policies and Methods of Application (Details) - Other Income (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Component of Operating Income [Abstract]	'		'
Equity investment income	$3		$3
AFUDC - equity	1		3
Other, net	-1		-1
Total other income	$3	[1]	$5	[1]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.

Note_2_Significant_Accounting_5

Note 2 - Significant Accounting Policies and Methods of Application (Details) - Potentially Dilutive Common Share Calculation (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Potentially Dilutive Common Share Calculation [Abstract]	'		'
Income from continuing operations (2) (in Dollars)	$334	[1],[2]	$149	[1],[2]
(Loss) income from discontinued operations, net of tax (3) (in Dollars)	-50	[1],[3]	1	[1],[3]
Net income attributable to AGL Resources Inc. (in Dollars)	$284	[1]	$150	[1]
Basic weighted average number of shares outstanding (4) (in Shares)	118.5	[1],[4]	117.4	[1],[4]
Effect of dilutive securities (in Shares)	0.4	[1]	0.3	[1]
Diluted weighted average number of shares outstanding (in Shares)	118.9	[1]	117.7	[1]
Basic earnings (loss) per common share	'		'
From continuing operations	$2.82	[1],[2]	$1.27	[1],[2]
From discontinued operations	($0.43)	[1],[2]	$0.01	[1],[2]
Basic earnings per common share attributable to AGL Resources Inc. common shareholders	$2.39	[1]	$1.28	[1]
Diluted earnings (loss) per common share	'		'
From continuing operations	$2.81	[1],[2]	$1.26	[1],[2]
From discontinued operations	($0.43)	[1],[2]	$0.01	[1],[2]
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders	$2.38	[1]	$1.27	[1]
[1]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
[2]	Excludes net income attributable to the noncontrolling interest.
[3]	For additional information on our discontinued operations, see Note 12.
[4]	Daily weighted average shares outstanding.

Note_3_Regulated_Operations_De

Note 3 - Regulated Operations (Details) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014
			Natural Gas Costs [Member]
Note 3 - Regulated Operations (Details) [Line Items]	'	'	'
Increase (Decrease) in Other Regulatory Assets	$228	($43)	$270

Note_3_Regulated_Operations_De1

Note 3 - Regulated Operations (Details) - Summary of Regulatory Assets and Liabilities (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
In Millions, unless otherwise specified
Regulatory assets	'		'		'
Regulatory assets, current	$250	[1]	$114	[1]	$72	[1]
Regulatory assets, long-term	696	[1]	705	[1]	868	[1]
Total regulatory assets	946	[1]	819	[1]	940	[1]
Regulatory liabilities	'		'		'
Regulatory liabilities, current	161	[1]	183	[1]	238	[1]
Regulatory liabilities, long-term	1,550	[1]	1,518	[1]	1,498	[1]
Total regulatory liabilities	1,711	[1]	1,701	[1]	1,736	[1]
Bad Debt Rider [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, current	41	[1]	41	[1]	39	[1]
Regulatory liabilities, long-term	14	[1]	17	[1]	20	[1]
Accumulated removal costs [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, current	27	[1]	27	[1]	17	[1]
Regulatory liabilities, long-term	1,456	[1]	1,445	[1]	1,413	[1]
Accrued natural gas costs [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, current	24	[1]	92	[1]	133	[1]
Seasonal Rates [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, current	20	[1]	'	[1]	20	[1]
Other Regulatory Liabilities [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, current	49	[1]	23	[1]	29	[1]
Regulatory liabilities, long-term	28	[1]	3	[1]	11	[1]
Regulatory Income Tax Liability [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, long-term	27	[1]	27	[1]	26	[1]
Unamortized investment tax credit [Member]	'		'		'
Regulatory liabilities	'		'		'
Regulatory liabilities, long-term	25	[1]	26	[1]	28	[1]
Deferred Natural Gas Costs [Member]	'		'		'
Regulatory assets	'		'		'
Regulatory assets, current	161	[1]	1	[1]	'	[1]
Recoverable Environmental Remediation Costs [Member]	'		'		'
Regulatory assets	'		'		'
Regulatory assets, current	38	[1]	45	[1]	28	[1]
Regulatory assets, long-term	419	[1]	433	[1]	415	[1]
Recoverable Pension And Other Retirement Benefit Costs [Member]	'		'		'
Regulatory assets	'		'		'
Regulatory assets, current	9	[1]	9	[1]	19	[1]
Regulatory assets, long-term	97	[1]	99	[1]	192	[1]
Other Regulatory Assets [Member]	'		'		'
Regulatory assets	'		'		'
Regulatory assets, current	42	[1]	59	[1]	25	[1]
Regulatory assets, long-term	43	[1]	36	[1]	48	[1]
Recoverable Regulatory Infrastructure Program Costs [Member]	'		'		'
Regulatory assets	'		'		'
Regulatory assets, long-term	57	[1]	55	[1]	125	[1]
Long-Term Debt Fair Value Adjustment [Member]	'		'		'
Regulatory assets	'		'		'
Regulatory assets, long-term	$80	[1]	$82	[1]	$88	[1]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.

Note_3_Regulated_Operations_De2

Note 3 - Regulated Operations (Details) - Estimated Recognition of Rate Making Assets (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
In Millions, unless otherwise specified
Regulatory Assets [Line Items]	'		'		'
Rate Making Asset	$946	[1]	$819	[1]	$940	[1]
Regulatory Assett Off Balance Sheet [Member]	'		'		'
Regulatory Assets [Line Items]	'		'		'
Rate Making Asset	$102		$93		$71
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.

Note_3_Regulated_Operations_De3

Note 3 - Regulated Operations (Details) - Change in Net Position of Deferred and Accrued Natural Gas Costs (USD $)

3 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Accrued natural gas costs [Member]

Accrued natural gas costs [Member]

Accrued natural gas costs [Member]

Natural Gas Costs [Member]

Natural Gas Costs [Member]

Deferred Natural Gas Costs [Member]

Deferred Natural Gas Costs [Member]

Deferred Natural Gas Costs [Member]

Note 3 - Regulated Operations (Details) - Change in Net Position of Deferred and Accrued Natural Gas Costs [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Deferred natural gas costs

$250

[1]

$72

[1]

$114

[1]

'

'

'

'

'

$161

[1]

$1

[1]

'

[1]

Deferred natural gas costs

228

-43

'

'

'

'

'

'

161

'

'

Accrued natural gas costs

-161

[1]

-238

[1]

-183

[1]

-24

[1]

-92

[1]

-133

[1]

'

'

'

'

'

Accrued natural gas costs

'

'

'

109

'

'

'

'

'

'

'

Total (1)

'

'

'

'

'

'

137

[2]

-133

[2]

'

'

'

Total (1)

'

'

'

'

'

'

$270

[2]

'

'

'

'

[1]

Amounts revised to include prior period adjustments. See Note 13 for additional information.

[2]

The $270 million change resulted from increased natural gas prices during the first quarter of 2014 compared to the first quarter of 2013, primarily driven by colder weather experienced in the current quarter. These costs will be fully recovered in future periods.

Note_3_Regulated_Operations_De4

Note 3 - Regulated Operations (Details) - Costs Related to Remediation of Former Operating Sites (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Environmental Exit Cost [Line Items]	'
Probabilistic model cost estimates, low estimate	$378
Probabilistic model cost estimates, high estimate	806
Engineering estimates	67
Amount recorded	440
Expected costs over next 12 months	82
Illinois Environmental [Member]	'
Environmental Exit Cost [Line Items]	'
Probabilistic model cost estimates, low estimate	211
Probabilistic model cost estimates, high estimate	461
Engineering estimates	42
Amount recorded	246
Expected costs over next 12 months	39
New Jersey Environmental [Member]	'
Environmental Exit Cost [Line Items]	'
Probabilistic model cost estimates, low estimate	139
Probabilistic model cost estimates, high estimate	233
Engineering estimates	6
Amount recorded	144
Expected costs over next 12 months	25
Georgia And Florida [Member]	'
Environmental Exit Cost [Line Items]	'
Probabilistic model cost estimates, low estimate	28
Probabilistic model cost estimates, high estimate	112
Engineering estimates	8
Amount recorded	39
Expected costs over next 12 months	10
North Carolina Environmental [Member]	'
Environmental Exit Cost [Line Items]	'
Probabilistic model cost estimates, low estimate	'
Probabilistic model cost estimates, high estimate	'
Engineering estimates	11
Amount recorded	11
Expected costs over next 12 months	$8

Note_4_Fair_Value_Measurements2

Note 4 - Fair Value Measurements (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'	'
Weather Derivative Premium	$1	$3	$2

Note_4_Fair_Value_Measurements3

Note 4 - Fair Value Measurements (Details) - Derivative Assets and Liabilities (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
In Millions, unless otherwise specified
Fair Value, Inputs, Level 1 [Member] | Natural Gas Derivatives [Member]	'		'		'
Natural gas derivatives	'		'		'
Derivative Assets	$18	[1]	$6	[1]	$14	[1]
Derivative Liabilities	-38		-79		-38
Fair Value, Inputs, Level 2 [Member] | Natural Gas Derivatives [Member]	'		'		'
Natural gas derivatives	'		'		'
Derivative Assets	50	[1]	67	[1]	49	[1]
Derivative Liabilities	-75		-79		-23
Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member]	'		'		'
Natural gas derivatives	'		'		'
Derivative Assets	'	[1]	'	[1]	6	[1]
Natural Gas Derivatives [Member]	'		'		'
Natural gas derivatives	'		'		'
Derivative Assets	137	[1],[2],[3]	116	[1],[2],[3]	103	[1],[2],[3]
Derivative Liabilities	-82	[2],[3]	-80	[2],[3]	-24	[2],[3]
Netting of cash collateral	69	[1]	43	[1]	40	[1]
Netting of cash collateral	$31		$78		$37
[1]	Balances of $1 million at March 31, 2014, $3 million at December 31, 2013 and $2 million at March 31, 2013 associated with certain weather derivatives have been excluded, as they are accounted for based on intrinsic value rather than fair value.
[2]	There were no significant unobservable inputs (Level 3) for any of the dates presented.
[3]	There were no significant transfers between Level 1, Level 2 or Level 3 for any of the dates presented.

Note_4_Fair_Value_Measurements4

Note 4 - Fair Value Measurements (Details) - Amortized Cost and Fair Value of Long-Term Debt (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
In Millions, unless otherwise specified
Note 4 - Fair Value Measurements (Details) - Amortized Cost and Fair Value of Long-Term Debt [Line Items]	'		'		'
Long-term debt carrying amount	$3,810		$3,813		$3,550
Fair Value, Inputs, Level 2 [Member]	'		'		'
Note 4 - Fair Value Measurements (Details) - Amortized Cost and Fair Value of Long-Term Debt [Line Items]	'		'		'
Long-term debt fair value (1)	$4,095	[1]	$3,956	[1]	$4,006	[1]
[1]	Fair value determined using Level 2 inputs.

Note_5_Derivative_Instruments_1

Note 5 - Derivative Instruments (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$82	'	'
Increase (Decrease) in Risk Management Assets and Liabilities	17	-18	'
Collateral Already Posted, Aggregate Fair Value	100	77	121
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months	3	'	'
Less Than Two Years [Member] | Natural Gas Derivatives [Member] | Minimum [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Derivative, Term of Contract	'2 years	'	'
Less Than Two Years [Member] | Natural Gas Derivatives [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Percent Of Derivative Contracts	97.00%	'	'
Expiring In Two To Six Years [Member] | Natural Gas Derivatives [Member] | Maximum [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Derivative, Term of Contract	'5 years	'	'
Expiring In Two To Six Years [Member] | Natural Gas Derivatives [Member] | Minimum [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Derivative, Term of Contract	'2 years	'	'
Expiring In Two To Six Years [Member] | Natural Gas [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Percent Of Derivative Contracts	3.00%	'	'
Weather Derivatives [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Derivative, Gain (Loss) on Derivative, Net	-5	-2	'
Maximum [Member]	'	'	'
Note 5 - Derivative Instruments (Details) [Line Items]	'	'	'
Derivative, Collateral, Obligation to Return Cash	$15	'	'

Note_5_Derivative_Instruments_2

Note 5 - Derivative Instruments (Details) - Net Long Natural Gas Contracts	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
	ft3		ft3		ft3
Hedge designation	'		'		'
Cash flow hedges	6,000,000,000	[1],[2]	6,000,000,000	[1]	6,000,000,000	[1]
Not designated as hedges	277,000,000,000	[1],[2]	183,000,000,000	[1]	304,000,000,000	[1]
Total hedges	283,000,000,000	[1],[2]	189,000,000,000	[1]	310,000,000,000	[1]
Hedge position	'		'		'
Short position	-2,491,000,000,000	[1],[2]	-2,622,000,000,000	[1]	-1,902,000,000,000	[1]
Long position	2,774,000,000,000	[1],[2]	2,811,000,000,000	[1]	2,212,000,000,000	[1]
Net long position	283,000,000,000	[1],[2]	189,000,000,000	[1]	310,000,000,000	[1]
[1]	Volumes related to Nicor Gas exclude variable-priced contracts, which are carried at fair value, but whose fair values are not directly impacted by changes in commodity prices.
[2]	Approximately 97% of these contracts have durations of two years or less and the remaining 3% expire between 2 and 5 years.

Note_5_Derivative_Instruments_3

Note 5 - Derivative Instruments (Details) - Gains and Losses on Derivative Instruments (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Nicor Gas [Member]	'	'
Note 5 - Derivative Instruments (Details) - Gains and Losses on Derivative Instruments [Line Items]	'	'
Realized losses related to hedging natural gas costs	$2	($1)
Elizabethtown Gas [Member]	'	'
Note 5 - Derivative Instruments (Details) - Gains and Losses on Derivative Instruments [Line Items]	'	'
Realized losses related to hedging natural gas costs	$3	($3)

Note_5_Derivative_Instruments_4

Note 5 - Derivative Instruments (Details) - Derivative Instruments on the Condensed Consolidated Statements of Financial Position (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
In Millions, unless otherwise specified
Designated as cash flow hedges and fair value hedges	'		'		'
Net amounts of assets and liabilities presented in our unaudited Condensed Consolidated Statements of Financial Position (3)	($82)		'		'
Current Natural Gas Contracts [Member] | Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	2		3		3
Liabilities	'		-1		-1
Current Natural Gas Contracts [Member] | Not Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	675	[1],[2]	691	[1],[2]	332
Liabilities	-703	[1],[2]	-761	[1],[2]	-327
Current Interest Rate Swap Agreements [Member] | Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	'	[1],[2]	'	[1],[2]	5
Liabilities	'	[1],[2]	'	[1],[2]	'
Long-Term Natural Gas Contracts [Member] | Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	757	[1]	900	[1]	386	[1]
Liabilities	-801	[1]	-982	[1]	-376	[1]
Gross amounts offset in our unaudited Condensed Consolidated Statements of Financial Position (2)	-619	[2]	-781	[2]	-275	[2]
Gross amounts offset in our unaudited Condensed Consolidated Statements of Financial Position (2)	719	[2]	902	[2]	352	[2]
Long-Term Natural Gas Contracts [Member] | Not Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	80	[1],[2]	206	[1],[2]	46
Liabilities	-98	[1],[2]	-220	[1],[2]	-48
Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	2	[1],[2]	3	[1],[2]	8
Liabilities	'	[1],[2]	-1	[1],[2]	-1
Net amounts of assets and liabilities presented in our unaudited Condensed Consolidated Statements of Financial Position (3)	138	[3]	119	[3]	111	[3]
Net amounts of assets and liabilities presented in our unaudited Condensed Consolidated Statements of Financial Position (3)	-82	[3]	-80	[3]	-24	[3]
Not Designated as Hedging Instrument [Member]	'		'		'
Designated as cash flow hedges and fair value hedges	'		'		'
Assets	755	[1],[2]	897	[1],[2]	378
Liabilities	($801)	[1],[2]	($981)	[1],[2]	($375)
[1]	The gross amounts of recognized assets and liabilities are netted within our unaudited Condensed Consolidated Statements of Financial Position to the extent that we have netting arrangements with the counterparties.
[2]	As required by the authoritative guidance related to derivatives and hedging, the gross amounts of recognized assets and liabilities above do not include cashcollateral held on deposit in broker margin accounts of $100 million as of March 31, 2014, $121 million as of December 31, 2013 and $77 million as of March 31, 2013. Cash collateral is included in the "Gross amounts offset in our unaudited Condensed Consolidated Statements of Financial Position" line of this table.
[3]	At March 31, 2014, December 31, 2013 and March 31, 2013 we held letters of credit from counterparties that would offset, under master netting arrangements, aninsignificant portion of these assets.

Note_5_Derivative_Instruments_5

Note 5 - Derivative Instruments (Details) - Derivative Instruments on the Consolidated Statements of Income (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Designated as cash flow hedges	'		'
Income tax benefit	'		$1
Net of tax	4	[1]	-2	[1]
Not designated as hedges (1)	'		'
Total losses on derivative instruments, net of tax	-13		-18
Cost of Sales [Member] | Cash Flow Hedging [Member]	'		'
Designated as cash flow hedges	'		'
Natural gas contracts - gain (loss) reclassified from OCI	3		'
Cost of Sales [Member] | Fair Value Hedging [Member]	'		'
Not designated as hedges (1)	'		'
Natural gas contracts - net value adjustments	2	[2],[3]	'	[2],[3]
Operating Expense [Member] | Cash Flow Hedging [Member]	'		'
Designated as cash flow hedges	'		'
Natural gas contracts - gain (loss) reclassified from OCI	1		'
Interest Expense [Member] | Cash Flow Hedging [Member]	'		'
Designated as cash flow hedges	'		'
Natural gas contracts - gain (loss) reclassified from OCI	'		-3
Sales [Member] | Fair Value Hedging [Member]	'		'
Not designated as hedges (1)	'		'
Natural gas contracts - net value adjustments	-30	[2]	-24	[2]
Cash Flow Hedging [Member]	'		'
Designated as cash flow hedges	'		'
Income tax benefit	'		1
Net of tax	4		-2
Fair Value Hedging [Member]	'		'
Not designated as hedges (1)	'		'
Income tax benefit	11	[2]	8	[2]
Net of tax	($17)	[2]	($16)	[2]
[1]	All amounts are net of income taxes. Amounts in parentheses indicate debits to accumulated other comprehensive loss.
[2]	Associated with the fair value of derivative instruments held at March 31, 2014 and 2013.
[3]	Excludes losses recorded in cost of goods sold associated with weather derivatives of $5 million for the three months ended March 31, 2014 and $2 million for the three months ended March 31, 2013.

Note_6_Employee_Benefit_Plans_1

Note 6 - Employee Benefit Plans (Details) - Components of Pension and Other Retirement Benefit Costs (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Pension Plan [Member]	'	'
Note 6 - Employee Benefit Plans (Details) - Components of Pension and Other Retirement Benefit Costs [Line Items]	'	'
Service cost	$6	$8
Interest cost	12	10
Expected return on plan assets	-16	-16
Recognized actuarial loss	5	8
Net periodic benefit cost	7	10
Other Postretirement Benefit Plan [Member]	'	'
Note 6 - Employee Benefit Plans (Details) - Components of Pension and Other Retirement Benefit Costs [Line Items]	'	'
Service cost	1	1
Interest cost	4	3
Expected return on plan assets	-2	-1
Net amortization of prior service cost	-1	-1
Recognized actuarial loss	1	2
Net periodic benefit cost	$3	$4

Note_7_Debt_and_Credit_Facilit2

Note 7 - Debt and Credit Facilities (Details) (USD $)	3 Months Ended						3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
			Commercial Paper [Member]	Commercial Paper [Member]	Commercial Paper [Member]	Commercial Paper [Member]	Commercial Paper [Member]	Maximum [Member]	Nicor Gas [Member]	Nicor Gas [Member]	Nicor Gas [Member]
			Minimum [Member]	Maximum [Member]	AGL Capital [Member]	Nicor Gas [Member]
Note 7 - Debt and Credit Facilities (Details) [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Effective Percentage	'	'	'	'	0.30%	0.20%	'	'	'	'	'
Debt Instrument, Term	'	'	'1 day	'108 days	'	'	'	'	'	'	'
Debt Instrument, Remaining Maturity Term	'	'	'1 day	'35 days	'	'	'	'	'	'	'
Proceeds from (Repayments of) Commercial Paper (in Dollars)	($430)	($509)	'	'	'	'	'	'	'	'	'
Proceeds from Short-term Debt, Maturing in More than Three Months (in Dollars)	'	'	'	'	'	'	50	'	'	'	'
Repayments of Short-term Debt, Maturing in More than Three Months (in Dollars)	'	'	'	'	'	'	$145	'	'	'	'
Ratio of Indebtedness to Net Capital	'	'	'	'	'	'	'	0.7	0.54	0.55	0.43

Note_7_Debt_and_Credit_Facilit3

Note 7 - Debt and Credit Facilities (Details) - Debt Schedule (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	5.00%	[1]	'		4.50%	[1]
Outstanding	$200		'		$226
Outstanding	3,610		3,813		3,324
Total debt	4,551		4,984		4,418
Unamortized debt premium, net	NaN, NaN		'		'
Unamortized debt premium, net	'	[1]	'		'	[1]
Unamortized debt premium, net	16		16		18
Commercial Paper [Member] | AGL Capital [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	0.30%	[1],[2]	'		0.50%	[1],[2]
Outstanding	440	[2]	857	[2]	868	[2]
Commercial Paper [Member] | Nicor Gas [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	0.20%	[1],[2]	'		0.40%	[1],[2]
Outstanding	301	[2]	314	[2]	'	[2]
Commercial Paper [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	0.30%	[1]	'		0.50%	[1]
Outstanding	741		1,171		868
Current Portion Long-Term Debt [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	5.00%	[1]	'		4.50%	[1]
Outstanding	200		'		225
Current Portion of Capital Leases [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Maturity date	NaN, NaN		'		'
Weighted average interest rate	'	[1]	'		5.00%	[1]
Outstanding	'		'		1
Senior Notes [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	5.00%	[1]	'		5.10%	[1]
Outstanding	2,625		2,825	[1]	2,325
First Mortgage Bonds [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	5.60%	[1]	'		5.60%	[1]
Outstanding	500		500	[1]	500
Gas Facility Revenue Bonds [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	0.90%	[1]	'		1.20%	[1]
Outstanding	200		200	[1]	200
Medium-term Notes [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	7.80%	[1]	'		7.80%	[1]
Outstanding	181		181	[1]	181
Long-Term Debt Principal [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	4.90%	[1]	'		5.00%	[1]
Outstanding	3,506		3,706		3,206
Fair Value Adjustment [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	'	[1],[3]	'		'	[1],[3]
Outstanding	88	[3]	91	[1],[3]	100	[3]
Long-Term Debt Non-Principal [Member]	'		'		'
Note 7 - Debt and Credit Facilities (Details) - Debt Schedule [Line Items]	'		'		'
Weighted average interest rate	'	[1]	'		'	[1]
Outstanding	$104		$107		$118
[1]	Interest rates are calculated based on the daily weighted average balance outstanding for the three months ended March 31.
[2]	As of March 31, 2014, the effective interest rates on our commercial paper borrowings were 0.3% for AGL Capital and 0.2% for Nicor Gas.
[3]	See Note 4 for additional information on our fair value measurements.

Note_7_Debt_and_Credit_Facilit4

Note 7 - Debt and Credit Facilities (Details) - Debt-to-Capitalization Ratios	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
AGL Resources Inc [Member]	'	'	'
Schedule of Capitalization [Line Items]	'	'	'
Debt-to-capitalization ratios	0.54	0.57	0.55
Nicor Gas [Member]	'	'	'
Schedule of Capitalization [Line Items]	'	'	'
Debt-to-capitalization ratios	0.54	0.55	0.43

Note_8_Equity_Details_Other_Co

Note 8 - Equity (Details) - Other Comprehensive Income (Loss) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013		Dec. 31, 2012
Other Comprehensive Income (Loss) [Abstract]	'		'		'		'
Cash flow hedges	$1	[1]	$1	[1]	$1	[1]	($3)	[1]
Retirement benefit plans	-136	[1]	-212	[1]	-137	[1]	-215	[1]
Total	-135	[1]	-211	[1]	-136	[1]	-218	[1]
Cash flow hedges - OCI, before reclassifications	4	[1]	2	[1]	'		'
Total - OCI, before reclassifications	4	[1]	2	[1]	'		'
Retirement benefit plans - OCI, before reclassifications	'	[1]	'	[1]	'		'
Cash flow hedges - Amounts reclassified from accumulated other comprehensive income	-4	[1]	2	[1]	'		'
Retirement benefit plans - Amounts reclassified from accumulated other comprehensive income	1	[1]	3	[1]	'		'
Total - Amounts reclassified from accumulated other comprehensive income	($3)	[1]	$5	[1]	'		'
[1]	All amounts are net of income taxes. Amounts in parentheses indicate debits to accumulated other comprehensive loss.

Note_8_Equity_Details_Reclassi

Note 8 - Equity (Details) - Reclassifications Out of Accumulated Other Comprehensive Loss (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Cash flow hedges	'		'
Interest rate contracts (3)	($46,000,000)		($45,000,000)
Total before income tax	549,000,000		250,000,000
Income tax benefit	203,000,000		91,000,000
Net of tax	284,000,000	[1]	150,000,000	[1]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Natural Gas Derivatives [Member]	'		'
Cash flow hedges	'		'
Natural gas contracts (2)	4,000,000	[2],[3]	'	[2],[3]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'		'
Cash flow hedges	'		'
Interest rate contracts (3)	'	[2],[4]	-3,000,000	[2],[4]
Total before income tax	4,000,000	[2]	-3,000,000	[2]
Income tax benefit	'	[2]	1,000,000	[2]
Net of tax	4,000,000	[2]	-2,000,000	[2]
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]	'		'
Cash flow hedges	'		'
Total before income tax	-2,000,000	[2]	-5,000,000	[2]
Income tax benefit	1,000,000	[2]	2,000,000	[2]
Net of tax	-1,000,000	[2]	-3,000,000	[2]
Retirement benefit plan amortization of	'		'
Actuarial losses (4)	-2,000,000	[2],[5]	-6,000,000	[5]
Prior service credits (4)	'	[2],[5]	1,000,000	[5]
Reclassification out of Accumulated Other Comprehensive Income [Member]	'		'
Cash flow hedges	'		'
Net of tax	$3,000,000	[2]	($5,000,000)	[2]
[1]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
[2]	Amounts in parentheses indicate debits, or reductions, to profit/loss and credits to accumulated other comprehensive loss. Except for retirement benefit plan amounts, the profit/loss impacts are immediate.
[3]	Amounts included within cost of goods sold.
[4]	Amounts included within interest expense, net.
[5]	Amortization of these accumulated other comprehensive loss components is included in the computation of net periodic benefit cost. See Note 6 for additional details about net periodic benefit cost.

Note_9_NonWholly_Owned_Entitie2

Note 9 - Non-Wholly Owned Entities (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Note 9 - Non-Wholly Owned Entities (Details) [Line Items]	'		'
Payments to Acquire Property, Plant, and Equipment	$161	[1]	$147	[1]
Payments of Ordinary Dividends, Noncontrolling Interest	17		17
South Star [Member] | AGL Resources Inc [Member]	'		'
Note 9 - Non-Wholly Owned Entities (Details) [Line Items]	'		'
Equity Method Investment, Ownership Percentage	85.00%		'
South Star [Member] | Piedmont [Member]	'		'
Note 9 - Non-Wholly Owned Entities (Details) [Line Items]	'		'
Payments of Ordinary Dividends, Noncontrolling Interest	'		17
South Star [Member]	'		'
Note 9 - Non-Wholly Owned Entities (Details) [Line Items]	'		'
Payments to Acquire Property, Plant, and Equipment	$2		$1
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.

Note_9_NonWholly_Owned_Entitie3

Note 9 - Non-Wholly Owned Entities (Details) - SouthStar’s Aassets and Liabilities (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'		'		'		'
Current assets	$3,589	[1],[2]	$2,895	[1],[2]	$2,530	[1],[2]	'
Goodwill and other intangible assets	1,967	[1],[2]	1,972	[1],[2]	1,953	[1],[2]	'
Long-term assets and other deferred debits	9,708	[1],[2]	9,683	[1],[2]	9,379	[1],[2]	'
Total assets	15,264	[1],[2]	14,550	[1],[2]	13,862	[1],[2]	'
Current liabilities	3,754	[1],[2]	3,118	[1],[2]	3,059	[1],[2]	'
Long-term liabilities and other deferred credits	7,667	[1],[2]	7,819	[1],[2]	7,310	[1],[2]	'
Total Liabilities	11,421	[1],[2]	10,937	[1],[2]	10,369	[1],[2]	'
Equity	3,843	[1],[2]	3,613	[1],[2]	3,493	[1],[2]	3,391
Total liabilities and equity	15,264	[1],[2]	14,550	[1],[2]	13,862	[1],[2]	'
South Star [Member]	'		'		'		'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'		'		'		'
Current assets	235	[1],[2],[3]	264	[1],[2],[3]	143	[1],[2],[3]	'
Goodwill and other intangible assets	131	[1],[2],[3]	133	[1],[2],[3]	'	[1],[2],[3]	'
Long-term assets and other deferred debits	16	[1],[2],[3]	13	[1],[2],[3]	10	[1],[2],[3]	'
Total assets	382	[1],[2],[3]	410	[1],[2],[3]	153	[1],[2],[3]	'
Current liabilities	106	[1],[2],[3]	95	[1],[2],[3]	51	[1],[2],[3]	'
Long-term liabilities and other deferred credits	'	[1],[2],[3]	'	[1],[2],[3]	'	[1],[2],[3]	'
Total Liabilities	106	[1],[2],[3]	95	[1],[2],[3]	51	[1],[2],[3]	'
Equity	276	[1],[2],[3]	315	[1],[2],[3]	102	[1],[2],[3]	'
Total liabilities and equity	$382	[1],[2],[3]	$410	[1],[2],[3]	$153	[1],[2],[3]	'
South Star Percentage To Consolidated [Member]	'		'		'		'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'		'		'		'
Current assets	7.00%	[1],[2],[4]	9.00%	[1],[2],[4]	6.00%	[4]	'
Goodwill and other intangible assets	7.00%	[1],[2],[4]	7.00%	[1],[2],[4]	'	[4]	'
Long-term assets and other deferred debits	'	[1],[2],[4]	'	[1],[2],[4]	'	[4]	'
Total assets	3.00%	[1],[2],[4]	3.00%	[1],[2],[4]	1.00%	[4]	'
Current liabilities	3.00%	[1],[2],[4]	3.00%	[1],[2],[4]	2.00%	[4]	'
Long-term liabilities and other deferred credits	'	[1],[2],[4]	'	[1],[2],[4]	'	[4]	'
Total Liabilities	1.00%	[1],[2],[4]	1.00%	[1],[2],[4]	'	[4]	'
Equity	7.00%	[1],[2],[4]	9.00%	[1],[2],[4]	3.00%	[4]	'
Total liabilities and equity	3.00%	[1],[2],[4]	3.00%	[1],[2],[4]	1.00%	[4]	'
[1]	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
[2]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[3]	These amounts reflect information for SouthStar and exclude intercompany eliminations and the balances of our wholly owned subsidiary with an 85% ownership interest in SouthStar.
[4]	SouthStar's percentage of the amount on our Statements of Financial Position.

Note_9_NonWholly_Owned_Entitie4

Note 9 - Non-Wholly Owned Entities (Details) - SouthStar’s Revenues and Expenses (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Variable Interest Entity [Line Items]	'		'
Operating revenues	$2,462	[1]	$1,612	[1]
Operating income	592	[1]	290	[1]
Cost of goods sold	1,400	[1]	920	[1]
Operation and maintenance	289	[1]	231	[1]
Depreciation and amortization	93	[1]	102	[1]
Total operating expenses	1,870	[1]	1,322	[1]
South Star [Member]	'		'
Variable Interest Entity [Line Items]	'		'
Operating revenues	374	[1]	250	[1]
Operating income	78	[1]	67	[1]
Cost of goods sold	270	[1]	164	[1]
Operation and maintenance	23	[1]	18	[1]
Depreciation and amortization	3	[1]	1	[1]
Total operating expenses	$296	[1]	$183	[1]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.

Note_9_NonWholly_Owned_Entitie5

Note 9 - Non-Wholly Owned Entities (Details) - Equity Method Investments (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Schedule of Equity Method Investments [Line Items]	'		'
Equity Method Investments	$83		$97
Income from Equity Method Investments	3		3
Triton [Member]	'		'
Schedule of Equity Method Investments [Line Items]	'		'
Equity Method Investments	67		72
Income from Equity Method Investments	2		2
Horizon Pipeline [Member]	'		'
Schedule of Equity Method Investments [Line Items]	'		'
Equity Method Investments	15		16
Income from Equity Method Investments	1		1
Other Equity Investments [Member]	'		'
Schedule of Equity Method Investments [Line Items]	'		'
Equity Method Investments	$1	[1]	$9	[1]
[1]	Includes our investment in Sawgrass Storage. In December 2013, the joint venture decided to terminate the development of the Sawgrass storage facility and reduced the carrying amount of the joint venture's long-lived assets to fair value.

Note_10_Commitments_Guarantees1

Note 10 - Commitments, Guarantees and Contingencies (Details) (USD $)	0 Months Ended		3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 07, 2013	Nov. 05, 2012	Mar. 31, 2014	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2009	Feb. 01, 2012
Note 10 - Commitments, Guarantees and Contingencies (Details) [Line Items]	'	'	'	'	'	'	'
Gas Balancing Volume Amount (in Cubic Feet)	'	'	'	4,800,000,000	'	'	'
Illinois Commission [Member]	'	'	'	'	'	'	'
Note 10 - Commitments, Guarantees and Contingencies (Details) [Line Items]	'	'	'	'	'	'	'
Loss Contingency, Damages Sought, Value	'	'	'	'	'	$85	'
Loss Contingency, Estimate of Possible Loss	'	'	'	'	'	'	64
Loss Contingency, Damages Awarded, Value	72	72	'	'	'	'	'
Loss Contingency Accrual, Period Increase (Decrease)	'	'	'	8	'	'	'
Loss Contingency Accrual	'	'	'	72	'	'	'
Loss Contingency, Damages Paid, Value	'	'	35	'	29	'	'
IAG [Member]	'	'	'	'	'	'	'
Note 10 - Commitments, Guarantees and Contingencies (Details) [Line Items]	'	'	'	'	'	'	'
Loss Contingency, Damages Sought, Value	'	'	'	'	'	255	'
CUB [Member]	'	'	'	'	'	'	'
Note 10 - Commitments, Guarantees and Contingencies (Details) [Line Items]	'	'	'	'	'	'	'
Loss Contingency, Damages Sought, Value	'	'	'	'	'	$305	'

Note_11_Segment_Information_De

Note 11 - Segment Information (Details)	3 Months Ended
	Mar. 31, 2014
Note 11 - Segment Information (Details) [Line Items]	'
Number of Operating Segments	4
Distribution Operations [Member]	'
Note 11 - Segment Information (Details) [Line Items]	'
Number of States in which Entity Operates	7

Note_11_Segment_Information_De1

Note 11 - Segment Information (Details) - Segment Reporting (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	$15,264	[1],[2]	$14,550	[1],[2]	$13,862	[1],[2]	'
Goodwill	1,827	[3]	1,827	[3]	1,822	[3]	1,776	[3]
Distribution Operations [Member] | Continuing Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	11,823	[2],[4],[5]	'		11,188	[2],[4],[5]	'
Distribution Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	'		11,634	[2],[6]	'		'
Goodwill	1,640	[3]	1,640	[3]	1,640	[3]	1,640	[3]
Retail Operations [Member] | Continuing Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	738	[2],[4],[5]	'		663	[2],[4],[5]	'
Retail Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	'		685	[2],[6]	'		'
Goodwill	173	[3]	173	[3]	168	[3]	122	[3]
Wholesale Services [Member] | Continuing Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	1,782	[2],[4],[5]	'		1,005	[2],[4],[5]	'
Wholesale Services [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	'		1,163	[2],[6]	'		'
Midstream Operations [Member] | Continuing Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	698	[2],[4],[5]	'		714	[2],[4],[5]	'
Midstream Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	'		713	[2],[6]	'		'
Goodwill	14	[3]	14	[3]	14	[3]	14	[3]
Other Segments [Member] | Continuing Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	9,844	[2],[4],[5],[7]	'		9,732	[2],[4],[5],[7]	'
Other Segments [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	'		10,160	[2],[6],[8]	'		'
Goodwill	'		'	[8]	'		'
Intersegment Eliminations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	'		-10,088	[2],[6]	'		'
Continuing Operations [Member]	'		'		'		'
Note 11 - Segment Information (Details) - Segment Reporting [Line Items]	'		'		'		'
Identifiable and total assets	15,000	[2],[4],[5]	14,267	[2],[6]	13,571	[2],[4],[5]	'
Goodwill	'		$1,827		'		'
[1]	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
[2]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[3]	Excludes goodwill at Tropical Shipping which is classified as held for sale. See Note 12 for additional information.
[4]	Wholesale services records its energy marketing and risk management revenues on a net basis. A reconciliation of our operating revenues and our intercompany revenues is shown in the following table.
[5]	Identifiable assets are those used in each segment's operations and exclude assets held for sale.
[6]	Identifiable assets are those assets used in each segment's operations and exclude assets held for sale.
[7]	Our "other" segment now also includes our investment in Triton, which was part of our cargo shipping segment that is classified as discontinued operations. For more information see Note 12.
[8]	Includes our investment in Triton, which was part of our cargo shipping segment that is classified as discontinued operations. For more information see Note 12.

Note_11_Segment_Information_De2

Note 11 - Segment Information (Details) - Intersegment Reporting (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Segment Reporting Information [Line Items]	'		'		'
Revenues	$2,462	[1]	$1,612	[1]	'
Operating expenses	'		'		'
Cost of goods sold	1,400	[1]	920	[1]	'
Operation and maintenance	289	[1]	231	[1]	'
Depreciation and amortization	93	[1]	102	[1]	'
Taxes other than income taxes	88	[1]	69	[1]	'
Total operating expenses	1,870	[1]	1,322	[1]	'
Operating income (loss)	592	[1]	290	[1]	'
Other income	3	[1]	5	[1]	'
EBIT	595	[1]	295	[1]	'
Identifiable and total assets	15,264	[1],[2]	13,862	[1],[2]	14,550	[1],[2]
Capital expenditures	161	[1]	147	[1]	'
Consolidation, Eliminations [Member] | Distribution Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	75	[1]	55	[1]	'
Consolidation, Eliminations [Member] | Retail Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	'	[1]	'	[1]	'
Consolidation, Eliminations [Member] | Wholesale Services [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	'	[1],[3]	'	[1],[3]	'
Consolidation, Eliminations [Member] | Midstream Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	'	[1]	'	[1]	'
Consolidation, Eliminations [Member] | Other Segments [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	'	[1],[4]	'	[1],[4]	'
Consolidation, Eliminations [Member] | Intercompany Eliminations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	-75	[1]	-55	[1]	'
Consolidation, Eliminations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	'	[1]	'	[1]	'
Operating Segments [Member] | Distribution Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	1,801	[1]	1,310	[1]	'
Operating Segments [Member] | Retail Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	406	[1]	302	[1]	'
Operating Segments [Member] | Wholesale Services [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	331	[1],[3]	39	[1],[3]	'
Operating Segments [Member] | Midstream Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	44	[1]	24	[1]	'
Operating Segments [Member] | Other Segments [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	3	[1],[4]	1	[1],[4]	'
Operating Segments [Member] | Intercompany Eliminations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	-123	[1]	-64	[1]	'
Operating Segments [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	2,462	[1]	1,612	[1]	'
Distribution Operations [Member] | Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	11,823	[1],[3],[5]	11,188	[1],[3],[5]	'
Distribution Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	1,726	[1]	1,255	[1]	'
Operating expenses	'		'		'
Cost of goods sold	1,202	[1]	765	[1]	'
Operation and maintenance	211	[1]	185	[1]	'
Depreciation and amortization	78	[1]	88	[1]	'
Taxes other than income taxes	82	[1]	64	[1]	'
Total operating expenses	1,573	[1]	1,102	[1]	'
Operating income (loss)	228	[1]	208	[1]	'
Other income	1	[1]	3	[1]	'
EBIT	229	[1]	211	[1]	'
Identifiable and total assets	'		'		11,634	[1],[6]
Capital expenditures	150	[1]	137	[1]	'
Retail Operations [Member] | Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	738	[1],[3],[5]	663	[1],[3],[5]	'
Retail Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	406	[1]	302	[1]	'
Operating expenses	'		'		'
Cost of goods sold	280	[1]	195	[1]	'
Operation and maintenance	37	[1]	31	[1]	'
Depreciation and amortization	8	[1]	6	[1]	'
Taxes other than income taxes	1	[1]	1	[1]	'
Total operating expenses	326	[1]	233	[1]	'
Operating income (loss)	80	[1]	69	[1]	'
Other income	'	[1]	'	[1]	'
EBIT	80	[1]	69	[1]	'
Identifiable and total assets	'		'		685	[1],[6]
Capital expenditures	3	[1]	1	[1]	'
Wholesale Services [Member] | Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	1,782	[1],[3],[5]	1,005	[1],[3],[5]	'
Wholesale Services [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	331	[1],[3]	39	[1],[3]	'
Operating expenses	'		'		'
Cost of goods sold	3	[1],[3]	10	[1],[3]	'
Operation and maintenance	36	[1],[3]	13	[1],[3]	'
Depreciation and amortization	'	[1],[3]	'	[1],[3]	'
Taxes other than income taxes	1	[1],[3]	1	[1],[3]	'
Total operating expenses	40	[1],[3]	24	[1],[3]	'
Operating income (loss)	291	[1],[3]	15	[1],[3]	'
Other income	'	[1],[3]	'	[1],[3]	'
EBIT	291	[1],[3]	15	[1],[3]	'
Identifiable and total assets	'		'		1,163	[1],[6]
Capital expenditures	1	[1],[3]	'	[1],[3]	'
Midstream Operations [Member] | Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	698	[1],[3],[5]	714	[1],[3],[5]	'
Midstream Operations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	44	[1]	24	[1]	'
Operating expenses	'		'		'
Cost of goods sold	36	[1]	12	[1]	'
Operation and maintenance	6	[1]	6	[1]	'
Depreciation and amortization	5	[1]	4	[1]	'
Taxes other than income taxes	1	[1]	1	[1]	'
Total operating expenses	48	[1]	23	[1]	'
Operating income (loss)	-4	[1]	1	[1]	'
Other income	1	[1]	1	[1]	'
EBIT	-3	[1]	2	[1]	'
Identifiable and total assets	'		'		713	[1],[6]
Capital expenditures	'	[1]	4	[1]	'
Other Segments [Member] | Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	9,844	[1],[3],[4],[5]	9,732	[1],[3],[4],[5]	'
Other Segments [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	3	[1],[4]	1	[1],[4]	'
Operating expenses	'		'		'
Cost of goods sold	'	[1],[4]	'	[1],[4]	'
Operation and maintenance	1	[1],[4]	-2	[1],[4]	'
Depreciation and amortization	2	[1],[4]	4	[1],[4]	'
Taxes other than income taxes	3	[1],[4]	2	[1],[4]	'
Total operating expenses	6	[1],[4]	4	[1],[4]	'
Operating income (loss)	-3	[1],[4]	-3	[1],[4]	'
Other income	1	[1],[4]	1	[1],[4]	'
EBIT	-2	[1],[4]	-2	[1],[4]	'
Identifiable and total assets	'		'		10,160	[1],[6],[7]
Capital expenditures	7	[1],[4]	5	[1],[4]	'
Intercompany Eliminations [Member] | Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	-9,885	[1],[3],[5]	-9,731	[1],[3],[5]	'
Intercompany Eliminations [Member]	'		'		'
Segment Reporting Information [Line Items]	'		'		'
Revenues	-48	[1]	-9	[1]	'
Operating expenses	'		'		'
Cost of goods sold	-121	[1]	-62	[1]	'
Operation and maintenance	-2	[1]	-2	[1]	'
Depreciation and amortization	'	[1]	'	[1]	'
Taxes other than income taxes	'	[1]	'	[1]	'
Total operating expenses	-123	[1]	-64	[1]	'
Operating income (loss)	'	[1]	'	[1]	'
Other income	'	[1]	'	[1]	'
EBIT	'	[1]	'	[1]	'
Capital expenditures	'	[1]	'	[1]	'
Continuing Operations [Member]	'		'		'
Operating expenses	'		'		'
Identifiable and total assets	$15,000	[1],[3],[5]	$13,571	[1],[3],[5]	$14,267	[1],[6]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
[3]	Wholesale services records its energy marketing and risk management revenues on a net basis. A reconciliation of our operating revenues and our intercompany revenues is shown in the following table.
[4]	Our "other" segment now also includes our investment in Triton, which was part of our cargo shipping segment that is classified as discontinued operations. For more information see Note 12.
[5]	Identifiable assets are those used in each segment's operations and exclude assets held for sale.
[6]	Identifiable assets are those assets used in each segment's operations and exclude assets held for sale.
[7]	Includes our investment in Triton, which was part of our cargo shipping segment that is classified as discontinued operations. For more information see Note 12.

Note_11_Segment_Information_De3

Note 11 - Segment Information (Details) - Operating Revenues (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	$2,462	[1]	$1,612	[1]
Thrid Party Gross Costs	1,400	[1]	920	[1]
Third Party Gross Revenues [Member] | Operating Segments [Member] | Wholesale Services [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	4,049		2,094
Intercompany Revenues [Member] | Operating Segments [Member] | Wholesale Services [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	298		140
Total Gross Revenues [Member] | Operating Segments [Member] | Wholesale Services [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	4,347		2,234
Third Party Gross Costs [Member] | Operating Segments [Member] | Wholesale Services [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Thrid Party Gross Costs	4,016		2,195
Operating Segments [Member] | Wholesale Services [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	331	[1],[2]	39	[1],[2]
Operating Segments [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	2,462	[1]	1,612	[1]
Wholesale Services [Member]	'		'
Segment Reporting, Revenue Reconciling Item [Line Items]	'		'
Revenues	331	[1],[2]	39	[1],[2]
Thrid Party Gross Costs	$3	[1],[2]	$10	[1],[2]
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Wholesale services records its energy marketing and risk management revenues on a net basis. A reconciliation of our operating revenues and our intercompany revenues is shown in the following table.

Note_12_Discontinued_Operation2

Note 12 - Discontinued Operations (Details) (USD $)	3 Months Ended						9 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Mar. 31, 2014
					Distributed Earnings of Foreign Subsidiaries [Member]	Distributed Earnings of Foreign Subsidiaries [Member]	Distributed Earnings of Foreign Subsidiaries [Member]	Tropical Shipping [Member]	Tropical Shipping [Member]	Tropical Shipping [Member]
					Tropical Shipping [Member]	Tropical Shipping [Member]	Tropical Shipping [Member]
Note 12 - Discontinued Operations (Details) [Line Items]	'		'		'	'	'	'	'	'
Proceeds from Divestiture of Businesses	'		'		'	'	'	$225,000,000	'	'
Discontinued Operation, Tax Effect of Discontinued Operation	-32,000,000	[1]	'	[1]	29,000,000	31,000,000	60,000,000	'	'	'
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	'		'		'	'	'	'	86,000,000	'
Goodwill, Impairment Loss, Net of Tax	'		'		'	'	'	'	'	19,000,000
Income Tax Expense (Benefit)	$203,000,000		$91,000,000		'	'	'	'	'	$0
[1]	Includes $31 million that was recorded in the first quarter of 2014 related to the cumulative foreign earnings for which no tax liabilities had been previously recorded.

Note_12_Discontinued_Operation3

Note 12 - Discontinued Operations (Details) - Assets and Liabilities of Tropical Shipping (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
In Millions, unless otherwise specified
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Cash and cash equivalents	$26	'	$27
Total current assets	264	283	291
Total current liabilities	36	40	34
Tropical Shipping [Member]	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Cash and cash equivalents	26	24	27
Short-term investments	3	1	2
Receivables	34	36	35
Inventories	9	9	9
Other	2	1	2
Total current assets	74	71	75
Property, plant and equipment, net	123	124	127
Goodwill	42	61	61
Intangible assets	19	19	20
Other	6	8	8
Total long-term assets and other deferred debits	190	212	216
Total assets held for sale	264	283	291
Other accounts payable - trade	9	11	8
Accrued expenses	4	7	4
Other	23	22	22
Total current liabilities	36	40	34
Total liabilities held for sale	$36	$40	$34

Note_12_Discontinued_Operation4

Note 12 - Discontinued Operations (Details) - Discontinued Operations from Statement of Income (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'		'
Operating revenues	$89		$87
Operating expenses	'		'
Cost of goods sold	54		53
Operation and maintenance	28		26
Depreciation and amortization	5		4
Taxes other than income taxes	1		3
Total operating expenses	107		86
Operating (loss) income	-18		1
(Loss) income before income taxes	-18		1
Income tax expense (2)	-32	[1]	'	[1]
(Loss) Income from discontinued operations, net of tax	-50	[2],[3]	1	[2],[3]
GoodwillImpairmentCharges [Member]	'		'
Operating expenses	'		'
Loss on sale and goodwill impairment (1)	$19	[4]	'	[4]
[1]	Includes $31 million that was recorded in the first quarter of 2014 related to the cumulative foreign earnings for which no tax liabilities had been previously recorded.
[2]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
[3]	For additional information on our discontinued operations, see Note 12.
[4]	Relates to $19 million of goodwill attributable to Tropical Shipping that was impaired as of March 31, 2014, based on the negotiated sales price.

Note_13_Revision_to_Prior_Peri2

Note 13 - Revision to Prior Period Financial Statements (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013		Jan. 01, 2013
Note 13 - Revision to Prior Period Financial Statements (Details) [Line Items]	'		'		'		'
Impact of Restatement on Opening Retained Earnings, Net of Tax	'		'		'		$45
Regulatory Assets, Noncurrent	696	[1]	868	[1]	705	[1]	'
Property, Plant and Equipment, Net	8,687		8,269		8,643		'
Net Income (Loss) Attributable to Parent	284	[2]	150	[2]	'		'
Depreciation, Depletion and Amortization, Nonproduction	93	[1]	102	[1]	'		'
Intangible Assets, Net (Excluding Goodwill)	140		131		145		'
Scenario, Adjustment [Member]	'		'		'		'
Note 13 - Revision to Prior Period Financial Statements (Details) [Line Items]	'		'		'		'
Regulatory Assets, Noncurrent	-87		'		'		'
Property, Plant and Equipment, Net	-14		'		'		'
Net Income (Loss) Attributable to Parent	-5		-4		'		'
Depreciation, Depletion and Amortization, Nonproduction	1		1		'		'
Intangible Assets, Net (Excluding Goodwill)	($11)		($5)		'		'
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.

Note_13_Revision_to_Prior_Peri3

Note 13 - Revision to Prior Period Financial Statements (Details) - Revisions to Condensed Consolidated Statements of Income (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Operating revenues	$2,462,000,000	[1]	$1,612,000,000	[1]
Operating expenses	'		'
Cost of goods sold	1,400,000,000	[1]	920,000,000	[1]
Operation and maintenance	289,000,000	[1]	231,000,000	[1]
Depreciation and amortization	93,000,000	[1]	102,000,000	[1]
Taxes other than income taxes	88,000,000	[1]	69,000,000	[1]
Total operating expenses	1,870,000,000	[1]	1,322,000,000	[1]
Operating income	592,000,000	[1]	290,000,000	[1]
Other income	3,000,000	[1]	5,000,000	[1]
Interest expense, net	-46,000,000		-45,000,000
Income before income taxes	549,000,000		250,000,000
Income tax expense	203,000,000		91,000,000
Income from continuing operations	346,000,000		159,000,000
(Loss) income from discontinued operations	-50,000,000	[2],[3]	1,000,000	[2],[3]
Net income	296,000,000		160,000,000
Less net income attributable to the noncontrolling interest	12,000,000		10,000,000
Net income attributable to AGL Resources Inc.	284,000,000	[2]	150,000,000	[2]
Basic earnings (loss) per common share (2)	'		'
Continuing operations (in Dollars per share)	$2.82	[2],[4]	$1.27	[2],[4]
Discontinued operations (in Dollars per share)	($0.43)	[2],[4]	$0.01	[2],[4]
Basic earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$2.39	[2]	$1.28	[2]
Diluted earnings (loss) per common share (2)	'		'
Continuing operations (in Dollars per share)	$2.81	[2],[4]	$1.26	[2],[4]
Discontinued operations (in Dollars per share)	($0.43)	[2],[4]	$0.01	[2],[4]
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$2.38	[2]	$1.27	[2]
Scenario, Previously Reported [Member]	'		'
Operating revenues	2,474,000,000	[5]	1,622,000,000	[5]
Operating expenses	'		'
Cost of goods sold	1,400,000,000	[5]	920,000,000	[5]
Operation and maintenance	289,000,000	[5]	232,000,000	[5]
Depreciation and amortization	93,000,000	[5],[6]	102,000,000	[5],[6]
Taxes other than income taxes	88,000,000	[5]	70,000,000	[5]
Total operating expenses	1,870,000,000	[5]	1,324,000,000	[5]
Operating income	604,000,000	[5]	298,000,000	[5]
Other income	3,000,000	[5]	5,000,000	[5]
Interest expense, net	-48,000,000	[5]	-46,000,000	[5]
Income before income taxes	559,000,000	[5]	257,000,000	[5]
Income tax expense	207,000,000	[5]	94,000,000	[5]
Income from continuing operations	352,000,000	[5]	163,000,000	[5]
(Loss) income from discontinued operations	-50,000,000	[5]	1,000,000	[5]
Net income	302,000,000	[5],[6]	164,000,000	[5],[6]
Less net income attributable to the noncontrolling interest	12,000,000	[5]	10,000,000	[5]
Net income attributable to AGL Resources Inc.	290,000,000	[5]	154,000,000	[5]
Basic earnings (loss) per common share (2)	'		'
Continuing operations (in Dollars per share)	$2.87	[4],[5]	$1.30	[4],[5]
Discontinued operations (in Dollars per share)	($0.43)	[4],[5]	$0.01	[4],[5]
Basic earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$2.44	[5]	$1.31	[5]
Diluted earnings (loss) per common share (2)	'		'
Continuing operations (in Dollars per share)	$2.87	[4],[5]	$1.30	[4],[5]
Discontinued operations (in Dollars per share)	($0.43)	[4],[5]	$0.01	[4],[5]
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	$2.44	[5]	$1.31	[5]
Restatement Adjustment [Member]	'		'
Operating revenues	-12,000,000		-10,000,000
Operating expenses	'		'
Operation and maintenance	'		-1,000,000
Taxes other than income taxes	'		-1,000,000
Total operating expenses	'		-2,000,000
Operating income	-12,000,000		-8,000,000
Interest expense, net	2,000,000		1,000,000
Income before income taxes	-10,000,000		-7,000,000
Income tax expense	-4,000,000		-3,000,000
Income from continuing operations	-6,000,000		-4,000,000
Net income	-6,000,000		-4,000,000
Net income attributable to AGL Resources Inc.	($6,000,000)		($4,000,000)
Basic earnings (loss) per common share (2)	'		'
Continuing operations (in Dollars per share)	($0.05)	[4]	($0.03)	[4]
Discontinued operations (in Dollars per share)	'	[4]	'	[4]
Basic earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	($0.05)		($0.03)
Diluted earnings (loss) per common share (2)	'		'
Continuing operations (in Dollars per share)	($0.06)	[4]	($0.04)	[4]
Discontinued operations (in Dollars per share)	'	[4]	'	[4]
Diluted earnings per common share attributable to AGL Resources Inc. common shareholders (in Dollars per share)	($0.06)		($0.04)
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Amounts revised and or include prior period adjustments. See Note 13 for additional information.
[3]	For additional information on our discontinued operations, see Note 12.
[4]	Excludes net income attributable to the noncontrolling interest.
[5]	Reflects the reclassification of the Tropical Shipping amounts as discontinued operations.
[6]	Reflects the reclassification of the Tropical Shipping amounts as held for sale.

Note_13_Revision_to_Prior_Peri4

Note 13 - Revision to Prior Period Financial Statements (Details) - Revisions to Condensed Consolidated Statements of Financial Position (USD $)	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Current assets	'		'		'		'
Regulatory assets	$250	[1]	$114	[1]	$72	[1]	'
Other	127		118		93		'
Total current assets	3,589	[1],[2]	2,895	[1],[2]	2,530	[1],[2]	'
Long-term assets and other deferred debits	'		'		'		'
Property, plant and equipment	11,054		10,938		10,450		'
Less accumulated depreciation	2,367		2,295		2,181		'
Property, plant and equipment, net	8,687		8,643		8,269		'
Regulatory assets	696	[1]	705	[1]	868	[1]	'
Intangible assets	140		145		131		'
Other	314		315		231		'
Total long-term assets and other deferred debits	11,675		11,655		11,332		'
Total assets	15,264	[1],[2]	14,550	[1],[2]	13,862	[1],[2]	'
Current liabilities	'		'		'		'
Accrued expenses	385		203		161		'
Total current liabilities	3,754	[1],[2]	3,118	[1],[2]	3,059	[1],[2]	'
Long-term liabilities and other deferred credits	'		'		'		'
Accumulated deferred income taxes	1,655		1,628		1,539		'
Total long-term liabilities and other deferred credits	7,667	[1],[2]	7,819	[1],[2]	7,310	[1],[2]	'
Total liabilities and other deferred credits	11,421	[1],[2]	10,937	[1],[2]	10,369	[1],[2]	'
Equity	'		'		'		'
Additional paid-in capital	2,060		2,054		2,020		'
Retained earnings	1,289		1,063		1,085		'
Total equity	3,843	[1],[2]	3,613	[1],[2]	3,493	[1],[2]	3,391
Total liabilities and equity	15,264	[1],[2]	14,550	[1],[2]	13,862	[1],[2]	'
Scenario, Previously Reported [Member]	'		'		'		'
Current assets	'		'		'		'
Regulatory assets	297	[3]	'		119	[3]	'
Other	127	[3]	'		95	[3]	'
Total current assets	3,637	[3]	'		2,577	[3]	'
Long-term assets and other deferred debits	'		'		'		'
Property, plant and equipment	11,068	[3]	'		10,463	[3]	'
Less accumulated depreciation	2,368	[3]	'		2,181	[3]	'
Property, plant and equipment, net	8,700	[3]	'		8,282	[3]	'
Regulatory assets	736	[3]	'		878	[3]	'
Intangible assets	151	[3]	'		136	[3]	'
Other	319	[3]	'		245	[3]	'
Total long-term assets and other deferred debits	11,739	[3]	'		11,363	[3]	'
Total assets	15,376	[3]	'		13,940	[3]	'
Current liabilities	'		'		'		'
Accrued expenses	390	[3]	'		162	[3]	'
Total current liabilities	3,753	[3]	'		3,060	[3]	'
Long-term liabilities and other deferred credits	'		'		'		'
Accumulated deferred income taxes	1,699	[3]	'		1,568	[3]	'
Total long-term liabilities and other deferred credits	7,711	[3]	'		7,339	[3]	'
Total liabilities and other deferred credits	11,465	[3]	'		10,399	[3]	'
Equity	'		'		'		'
Additional paid-in capital	2,059	[3]	'		2,019	[3]	'
Retained earnings	1,358	[3]	'		1,134	[3]	'
Total equity	3,911	[3]	'		3,541	[3]	'
Total liabilities and equity	$15,376	[3]	'		$13,940	[3]	'
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Reflects the reclassification of the Tropical Shipping amounts as held for sale. See Note 12 for additional information.
[3]	Reflects the reclassification of the Tropical Shipping amounts as held for sale.

Note_13_Revision_to_Prior_Peri5

Note 13 - Revision to Prior Period Financial Statements (Details) - Revisions to Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Cash flows from operating activities	'		'
Net income	$296		$160
Adjustments to reconcile net income to net cash flow provided by operating activities	'		'
Depreciation and amortization	93	[1]	102	[1]
Deferred income taxes	8		-25
Changes to certain assets and liabilities	'		'
Other, net	63		33
Net cash flow provided by operating activities	853		850
Scenario, Previously Reported [Member]	'		'
Cash flows from operating activities	'		'
Net income	302	[2],[3]	164	[2],[3]
Adjustments to reconcile net income to net cash flow provided by operating activities	'		'
Depreciation and amortization	93	[2],[3]	102	[2],[3]
Deferred income taxes	42	[3]	-24	[3]
Changes to certain assets and liabilities	'		'
Other, net	23	[3]	28	[3]
Net cash flow provided by operating activities	853	[3]	850	[3]
Restatement Adjustment [Member]	'		'
Cash flows from operating activities	'		'
Net income	-6		-4
Adjustments to reconcile net income to net cash flow provided by operating activities	'		'
Deferred income taxes	-34		-1
Changes to certain assets and liabilities	'		'
Other, net	$40		$5
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.
[2]	Reflects the reclassification of the Tropical Shipping amounts as discontinued operations.
[3]	Reflects the reclassification of the Tropical Shipping amounts as held for sale.

Note_13_Revision_to_Prior_Peri6

Note 13 - Revision to Prior Period Financial Statements (Details) - Revisions to Previously Reported Intangible Assets Disclosures (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Scenario, Previously Reported [Member] | Customer Relationships [Member]	'	'
Customer relationships	'	'
Gross	$130	$99
Accumulated amortization	-18	-7
Net	112	92
Scenario, Previously Reported [Member] | Trade Names [Member]	'	'
Customer relationships	'	'
Gross	45	46
Accumulated amortization	-6	-3
Net	39	43
Restatement Adjustment [Member] | Customer Relationships [Member]	'	'
Customer relationships	'	'
Accumulated amortization	-12	-6
Net	-12	-6
Restatement Adjustment [Member] | Trade Names [Member]	'	'
Customer relationships	'	'
Gross	'	1
Accumulated amortization	1	1
Net	1	2
Customer Relationships [Member]	'	'
Customer relationships	'	'
Gross	130	99
Accumulated amortization	-30	-13
Net	100	86
Trade Names [Member]	'	'
Customer relationships	'	'
Gross	45	47
Accumulated amortization	-5	-2
Net	$40	$45

Note_14_Subsequent_Events_Deta

Note 14 - Subsequent Events (Details) (USD $)	3 Months Ended				0 Months Ended			0 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Apr. 11, 2014	Apr. 11, 2014	Apr. 11, 2014	Apr. 11, 2014	Apr. 11, 2014
					Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
					Scenario, Forecast [Member]	Annual Lease Receivable [Member]	Dalton Pipeline Arrangement 1 [Member]	Dalton Pipeline Arrangement 2 [Member]	Dalton Pipeline Arrangement 2 [Member]
					Dalton Pipeline Arrangement 1 [Member]	Dalton Pipeline Arrangement 2 [Member]	mi	Atlanta Gas Light [Member]
								ft3
Note 14 - Subsequent Events (Details) [Line Items]	'		'		'	'	'	'	'
Business Acquisition, Percentage of Voting Interests Acquired	'		'		'	'	50.00%	'	'
Dalton Lateral Pipeline Length	'		'		'	'	106	'	'
Payments to Acquire Property, Plant, and Equipment	$161	[1]	$147	[1]	$210	'	'	'	'
Undivided Ownership Interest to Be Leased	'		'		'	'	'	'	50.00%
Operating Leases, Future Minimum Payments Receivable	'		'		'	$26	'	'	'
Lessor Leasing Arrangements, Operating Leases, Term of Contract	'		'		'	'	'	'	'25 years
Contracted Firm Capacity	'		'		'	'	'	240,000,000	'
[1]	Amounts revised to include prior period adjustments. See Note 13 for additional information.