WEC Energy (WEC) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) $ in Billions	9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015
Entity Information [Line Items]
Entity Registrant Name	WEC Energy Group, Inc.
Entity Central Index Key	783,325
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding	315,684,451
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$ 14.2

Condensed Consolidated Income S

Condensed Consolidated Income Statements - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Operating revenues	$ 1,698.7	$ 1,033.3	$ 4,077.8	$ 3,772
Cost of Sales	590.6	407.4	1,557.5	1,735.9
Other operation and maintenance	535.9	249.4	1,153.6	780.8
Depreciation and amortization	176.5	99.8	382.6	295.2
Property and revenue taxes	50	30.6	113.8	91.5
Total operating expenses	1,353	787.2	3,207.5	2,903.4
Operating income	345.7	246.1	870.3	868.6
Equity in earnings of transmission affiliate	40	18	70.4	52.8
Other Income, net	11.1	2.9	40.2	12.1
Interest expense	103.8	60.4	225.6	181.7
Other expense	(52.7)	(39.5)	(115)	(116.8)
Income before income taxes	293	206.6	755.3	751.8
Income Tax Expense	110.5	80.3	296.1	284.9
Net income	$ 182.5	$ 126.3	$ 459.2	$ 466.9
Earnings per share
Basic	$ 0.58	$ 0.56	$ 1.79	$ 2.07
Diluted	$ 0.58	$ 0.56	$ 1.78	$ 2.05
Weighted average common shares outstanding
Basic	315.7	225.5	256.2	225.6
Diluted	317.1	227.4	257.8	227.6
Dividends per share of common stock	$ 0	$ 0.39	$ 1.29	$ 1.17
Transmission Affiliate
Equity in earnings of transmission affiliate	$ 40	$ 18	$ 70.4	$ 52.8

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 182.5	$ 126.3	$ 459.2	$ 466.9
Derivatives accounted for as cash flow hedges
Gains on settlement, net of tax of $7.6 million	0	0	11.4	0
Reclassification of gains to net income, net of tax	(0.4)	0	(0.5)	0
Other comprehensive (loss) income, net of tax	(0.4)	0	10.9	0
Comprehensive income	$ 182.1	$ 126.3	$ 470.1	$ 466.9

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Gains on settlement, tax	$ 0	$ 0	$ 7.6	$ 0

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment
In service	$ 25,741.5	$ 15,509
Accumulated depreciation	(7,930.6)	(4,485.1)
Property, Plant and Equipment in Service, Net	17,810.9	11,023.9
Construction work in progress	936.4	191.8
Leased facilities, net	37.9	42
Net Property, Plant and Equipment	18,785.2	11,257.7
Investments
Equity investment in transmission affiliate	999.4	424.1
Other	97	32.8
Total Investments	1,096.4	456.9
Current Assets
Cash and cash equivalents	22.2	61.9
Accounts receivable and unbilled revenues, net of reserves of $128.7 and $74.5, respectively	844.7	643.4
Materials, supplies and inventories	719.8	400.6
Assets held for sale	140.2	0
Deferred income taxes	250.8	242.7
Other	204.2	186.8
Total Current Assets	2,181.9	1,535.4
Deferred Charges and Other Assets
Regulatory assets	2,805.5	1,271.2
Goodwill	3,389.1	441.9
Other long-term assets	511.5	200.3
Total Deferred Charges and Other Assets	6,706.1	1,913.4
Total Assets	28,769.6	15,163.4
Capitalization
Common stock - $.01 par value; 325,000,000 shares authorized; 315,684,451 and 225,517,339 shares outstanding, respectively	3.2	2.3
Additional Paid in Capital	4,350.6	300.1
Retained Earnings	4,264.9	4,117
Accumulated other comprehensive income	11.2	0.3
Preferred stock of subsidiaries	81.5	30.4
Long-term debt	8,727	4,186.4
Total Capitalization	17,438.4	8,636.5
Current Liabilities
Current portion of long-term debt	606	424.1
Short-term debt	661.5	617.6
Accounts payable	777.6	363.3
Accrued payroll and benefits	154.9	95.1
Other	466.8	168.6
Total Current Liabilities	2,666.8	1,668.7
Deferred Credits and Other Liabilities
Regulatory liabilities	1,312.3	830.6
Deferred income taxes	4,690.4	2,906.7
Deferred revenue, net	588.1	614.1
Pension and other postretirement benefit obligations	427.7	203.8
Environmental Remediation	611.5	32.6
Other long-term liabilities	1,034.4	270.4
Total Deferred Credits and Other Liabilities	8,664.4	4,858.2
Total Capitalization and Liabilities	28,769.6	15,163.4
Allowance for Doubtful Accounts Receivable, Current	$ 128.7	$ 74.5
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	325,000,000	325,000,000
Common Stock, Shares, Outstanding	315,684,451	225,517,339

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities
Net income	$ 459.2	$ 466.9
Reconciliation to cash
Depreciation and amortization	390.9	312.9
Deferred income taxes and investment tax credits, net	220.1	258.5
Contributions to pension and other postretirement plans	(109.3)	(12)
Change in -
Accounts receivable and unbilled revenues	269.5	221.1
Inventories	(101.4)	(49.9)
Other current assets	75.6	37.2
Accounts payable	(55.9)	(27.7)
Accrued taxes, net	57.9	(10.3)
Other current liabilities	40	(36.8)
Other, net	(173.4)	(125.3)
Net Cash Provided by Operating Activities	1,073.2	1,034.6
Investing Activities
Capital expenditures	(765.1)	(513)
Cost of Removal, Net of Salvage	(26.7)	(18.2)
Business acquisition, net of cash acquired of $156.3 million	(1,329.9)	0
Cash acquired from acquisition	156.3
Investment in transmission affiliate	(5.6)	(10.5)
Proceeds from asset sales	26.7	0
Other, net	4.7	12.8
Net Cash Used in Investing Activities	(2,095.9)	(528.9)
Financing Activities
Exercise of stock options	26.4	31.7
Purchase of common stock	(66.1)	(84.2)
Dividends paid on common stock	(310.9)	(264)
Issuance of long-term debt	1,650	250
Retirement of long-term debt	(27.1)	(322)
Change in short-term debt	(270.5)	(61.6)
Other, net	(18.8)	7.1
Net Cash Provided by (Used in) Financing Activities	983	(443)
Net Change in Cash and Cash Equivalents	(39.7)	62.7
Cash and Cash Equivalents at Beginning of Period	61.9	26
Cash and Cash Equivalents at End of Period	$ 22.2	$ 88.7

General Information

General Information	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
GENERAL INFORMATION	GENERAL INFORMATION On June 29, 2015 , Wisconsin Energy Corporation acquired Integrys, and the combined company was renamed WEC Energy Group, Inc. The Company serves approximately 1.6 million electric customers and 2.8 million natural gas customers, and it owns approximately 60% of ATC. See Note 2, Acquisition, for more information on this acquisition. As used in these notes, the term "financial statements" refers to the condensed consolidated financial statements. This includes the condensed consolidated income statements, condensed consolidated statements of comprehensive income, condensed consolidated balance sheets, and condensed consolidated statements of cash flows, unless otherwise noted. In this report, when we refer to "the Company," "us," "we," "our," or "ours," we are referring to WEC Energy Group and all of its subsidiaries. We have prepared the unaudited interim financial statements presented in this Form 10-Q pursuant to the rules and regulations of the SEC and United States Generally Accepted Accounting Principles (GAAP). Accordingly, these financial statements do not include all of the information and footnotes required by GAAP for annual financial statements. These financial statements should be read in conjunction with the consolidated financial statements and footnotes in our Annual Report on Form 10-K for the year ended December 31, 2014 . Financial results for an interim period may not give a true indication of results for the year. In particular, the results of operations for the three and nine months ended September 30, 2015 , are not necessarily indicative of expected results for 2015 due to the acquisition of Integrys, seasonal variations, and other factors. In management's opinion, we have included all adjustments, normal and recurring in nature, necessary for a fair presentation of our financial results.

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
ACQUISITION	ACQUISITION On June 29, 2015 , Wisconsin Energy acquired 100% of the outstanding common shares of Integrys, a provider of regulated natural gas and electricity, as well as nonregulated renewable energy and compressed natural gas (CNG) products and services. Integrys also holds a 34% interest in ATC, a for-profit transmission company regulated by the Federal Energy Regulatory Commission (FERC). The acquisition of Integrys provides increased scale, the potential for long-term cost savings through a combination of lower capital and operating costs, and the potential for operating efficiencies. Purchase Price Pursuant to the Agreement and Plan of Merger, dated as of June 22, 2014, between Integrys and Wisconsin Energy Corporation (Merger Agreement), Integrys’s shareholders received 1.128 shares of Wisconsin Energy common stock and $18.58 in cash per share of Integrys common stock. The total consideration transferred was based on the closing price of Wisconsin Energy common stock on June 29, 2015 , and was calculated as follows: Consideration Paid (in millions, except per share amounts) Stock Cash Total Integrys common shares outstanding at June 29, 2015 79,963,091 79,963,091 Exchange ratio 1.128 Wisconsin Energy shares issued for Integrys shares * 90,187,884 Closing price of Wisconsin Energy common shares on June 29, 2015 $45.16 Fair value of common stock issued $ 4,072.9 $ 4,072.9 Cash paid per share of Integrys shares outstanding $18.58 Fair value of cash paid for Integrys shares * $ 1,486.2 $ 1,486.2 Consideration attributable to settlement of equity awards, net of tax $ 24.0 $ 24.0 Total purchase price $ 4,072.9 $ 1,510.2 $ 5,583.1 * Fractional shares of 10,483 totaling $0.5 million were paid in cash. All Integrys unvested stock-based compensation awards became fully vested upon the close of the transaction and were either paid to award recipients in cash, or the value of the awards was deferred into a deferred compensation plan. In addition, all vested but unexercised Integrys stock options were paid in cash. In accordance with accounting guidance for business combinations, the expense caused by the acceleration of the vesting was an expense related to the acquisition. Allocation of Purchase Price The Integrys assets acquired and liabilities assumed were measured at estimated fair value as defined in the accounting guidance. Substantially all of Integrys's operations are subject to the rate-setting authority of federal and state regulatory commissions. These operations are accounted for in accordance with GAAP accounting guidance for regulated operations. In addition, the underlying assets and liabilities of ATC are regulated by FERC. The fair values of Integrys's assets and liabilities subject to these rate-setting provisions approximate their carrying values, and the assets and liabilities acquired and pro forma financial information do not reflect any adjustments related to these amounts. The excess of the purchase price over the estimated fair values of the assets acquired and liabilities assumed was recognized as goodwill. The goodwill reflects the value paid for the increased scale and efficiencies as a result of the combination. The goodwill recognized is not deductible for income tax purposes, and as such, no deferred taxes have been recorded related to goodwill. The allocation of goodwill to our reportable segments has not yet been completed. In the third quarter of 2015, adjustments were made to the estimated fair values of the assets acquired and liabilities assumed as additional information was obtained. The preliminary purchase price allocation is as follows: (in millions) Current assets $ 1,178.2 Net property, plant and equipment 7,097.9 Goodwill 2,947.2 Deferred charges and other assets, excluding goodwill 2,393.7 Current liabilities, including current maturities of long-term debt (1,261.3 ) Deferred credits and other liabilities (3,774.0 ) Long-term debt (2,947.5 ) Preferred stock of subsidiary (51.1 ) Total purchase price $ 5,583.1 Conditions of Approval The acquisition was subject to the approvals of various government agencies, including the FERC, Federal Communications Commission (FCC), Public Service Commission of Wisconsin (PSCW), Illinois Commerce Commission (ICC), Michigan Public Service Commission (MPSC), and Minnesota Public Utilities Commission (MPUC). Approvals were obtained from all agencies subject to several conditions. The PSCW order includes the following conditions: • Wisconsin Electric Power Company (Wisconsin Electric) and Wisconsin Gas LLC (Wisconsin Gas) will be subject to an earnings sharing mechanism for three years beginning January 1, 2016. Under the earnings sharing mechanism, if either company earns above its authorized return, 50% of the first 50 basis points of additional utility earnings will be shared with customers. For Wisconsin Electric, the additional utility earnings will be used to reduce the company’s transmission escrow. For Wisconsin Gas, additional utility earnings will be used to reduce the costs of the Western Gas Lateral. All utility earnings above the first 50 basis points will be used to reduce the transmission escrow for Wisconsin Electric or reduce the costs of the Western Gas Lateral for Wisconsin Gas. • Any future electric generation projects affecting Wisconsin ratepayers submitted by us or our subsidiaries will first consider the extent to which existing intercompany resources can meet energy and capacity needs. In September 2015, Wisconsin Public Service Corporation (WPS) and Wisconsin Electric filed a joint integrated resource plan with the PSCW for their combined loads, which indicated that no new generation is currently needed. The ICC order included a base rate freeze for The Peoples Gas Light and Coke Company (PGL) and North Shore Gas Company (NSG) effective for two years after the close of the acquisition. This base rate freeze does not impact our ability to adjust rates through various riders or the gas supply cost recovery mechanism. We do not believe that the conditions set forth in the various regulatory orders approving the acquisition will have a material impact on our operations or financial results. Pro Forma Information The following unaudited pro forma financial information reflects the consolidated results and amortization of purchase price adjustments as if the acquisition had taken place on January 1, 2014. The unaudited pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved or our future consolidated results. The pro forma financial information does not reflect any potential cost savings from operating efficiencies resulting from the acquisition and does not include certain acquisition-related costs. Three Months Ended September 30 Nine Months Ended September 30 (in millions, except per share amounts) 2015 2014 2015 2014 Unaudited Pro Forma Financial Information Operating Revenues $ 1,698.7 $ 1,689.8 $ 5,878.8 $ 6,898.0 Net Income $ 185.5 $ 210.7 $ 664.9 $ 712.1 Earnings per share (Basic) $ 0.59 $ 0.67 $ 2.11 $ 2.26 Earnings per share (Diluted) $ 0.58 $ 0.66 $ 2.10 $ 2.24 Impact of Acquisition As a result of the acquisition, our ownership of ATC increased to approximately 60% . We have made commitments with respect to our voting rights of the combined ownership of ATC, which are included as enforceable conditions in the orders approving the acquisition by the FERC and the PSCW. We also expect that ATC's governance documents will include these voting commitments. Under GAAP, these commitments do not allow for the consolidation of ATC in our financial statements and the 60% ownership is accounted for as an equity method investment subsequent to the close of the acquisition. See Note 13, Investment in ATC, for more information . In connection with the acquisition, WEC Energy Group and its subsidiaries recorded pre-tax acquisition costs of $6.5 million and $80.2 million during the three and nine months ended September 30, 2015, and $3.6 million and $8.6 million for the same periods in 2014, respectively. These costs consisted of employee-related expenses, professional fees, and other miscellaneous costs. They are recorded in the other operation and maintenance line item on the condensed consolidated income statements. Our revenues for the three and nine months ended September 30, 2015, include revenues attributable to Integrys of $633.4 million . Included in our net income for the three and nine months ended September 30, 2015, is net income attributable to Integrys of $46.2 million and $19.6 million , respectively.

Dispositions

Dispositions	9 Months Ended
	Sep. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
DISPOSITIONS	DISPOSITIONS Corporate and Other Segment—Potential Sale of Integrys Transportation Fuels, LLC (ITF) In the third quarter of 2015, we began to actively market ITF for sale with the use of outside consultants. ITF is a provider of CNG fueling services and a single-source provider of CNG fueling facility design, construction, operation and maintenance. The potential sale of ITF meets the criteria to qualify as held for sale but does not meet the requirements to qualify as a discontinued operation. The potential sale of ITF does not represent a shift in our corporate strategy and will not have a major effect on our operations and financial results. Therefore, ITF's results of operations remain in continuing operations. The following table shows the carrying values of the major classes of assets and liabilities included as held for sale on the balance sheet: (in millions) September 30, 2015 Property, plant and equipment, net of accumulated depreciation of $6.4 $ 46.2 Accounts receivable and unbilled revenues 42.9 Materials, supplies and inventories 16.6 Other current assets 5.1 Other long-term assets 29.4 Total assets $ 140.2 Accounts payable $ 11.9 Accrued payroll and benefits 1.8 Other current liabilities 7.1 Pension and other postretirement benefit obligations 0.4 Other long-term liabilities 0.4 Total liabilities * $ 21.6 * Included in other current liabilities on the balance sheet.

Common Equity

Common Equity	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
COMMON EQUITY	Stock Option Activity The following table identifies non-qualified stock options granted by the Compensation Committee of the Board of Directors (Compensation Committee): Nine Months Ended September 30 2015 2014 Non-qualified stock options granted 516,475 899,500 Estimated fair value per non-qualified stock option $ 5.29 $ 4.18 Assumptions used to value the options using a binomial option pricing model: Risk-free interest rate 0.1% – 2.1% 0.1% – 3.0% Dividend yield 3.7 % 3.8 % Expected volatility 18.0 % 18.0 % Expected forfeiture rate 2.0 % 2.0 % Expected life (years) 5.8 5.8 The risk-free interest rate is based on the U.S. Treasury interest rate with a term consistent with the expected life of the stock options. Dividend yield, expected volatility, expected forfeiture rate, and expected life assumptions are based on our historical experience. The following is a summary of our stock option activity for the three and nine months ended September 30, 2015 : Weighted-Average Remaining Aggregate Number of Weighted-Average Contractual Life Intrinsic Value Stock Options Options Exercise Price (in years) (in millions) Outstanding as of July 1, 2015 6,750,930 $ 32.32 Granted — $ — Exercised (599,752 ) $ 23.72 Outstanding as of September 30, 2015 6,151,178 $ 33.16 Outstanding as of January 1, 2015 6,770,194 $ 29.99 Granted 516,475 $ 52.90 Exercised (1,135,491 ) $ 23.25 Outstanding as of September 30, 2015 6,151,178 $ 33.16 5.8 $ 117.2 Exercisable as of September 30, 2015 3,419,728 $ 26.49 4.0 $ 88.0 The intrinsic value of options exercised was $15.8 million and $31.2 million for the three and nine months ended September 30, 2015 , and $12.7 million and $30.2 million for the same periods in 2014 , respectively. Cash received from options exercised was $26.4 million and $31.7 million for the nine months ended September 30, 2015 , and 2014 , respectively. The actual tax benefit realized for the tax deductions from option exercises for the same periods was $12.5 million and $12.1 million , respectively. Options to purchase 516,475 shares of common stock with an exercise price of $52.90 were outstanding during the third quarter of 2015 , but were not included in the computation of diluted earnings per share because they were anti-dilutive. As of September 30, 2015 , total compensation cost related to non-vested stock options not yet recognized was approximately $2.3 million , which is expected to be recognized over the next 17 months on a weighted-average basis. Restricted Shares The following restricted stock activity occurred during the three and nine months ended September 30, 2015 : Weighted-Average Restricted Shares Number of Shares Grant Date Fair Value Outstanding as of July 1, 2015 147,214 $ 45.43 Granted 82,943 $ 49.17 Released — $ — Forfeited (181 ) $ 46.16 Outstanding as of September 30, 2015 229,976 $ 46.78 Outstanding as of January 1, 2015 155,479 $ 38.45 Granted 143,107 $ 51.13 Released (68,429 ) $ 36.95 Forfeited (181 ) $ 46.16 Outstanding as of September 30, 2015 229,976 $ 46.78 On July 31, 2015, the Compensation Committee awarded certain officers and other employees of WEC Energy Group and its subsidiaries an aggregate of 82,943 shares of restricted stock for the key role each played in WEC Energy Group's acquisition of Integrys. The restricted stock vests in three equal installments on January 29, 2016; January 31, 2017; and, July 31, 2018. We recognize the grant date fair value of restricted stock awards in expense over the vesting period of the awards. The intrinsic value of restricted stock vesting was zero and $3.7 million for the three and nine months ended September 30, 2015 , and zero and $2.7 million for the same periods in 2014 , respectively. The actual tax benefit realized for the tax deductions from released restricted shares was zero and $1.3 million for the three and nine months ended September 30, 2015 , and zero and $1.0 million for the same periods in 2014 , respectively. As of September 30, 2015 , total compensation cost related to restricted stock not yet recognized was approximately $3.8 million , which is expected to be recognized over the next 22 months on a weighted-average basis. Performance Units In January 2015 and 2014 , the Compensation Committee granted 195,365 and 233,735 performance units, respectively, to officers and other key employees under the Wisconsin Energy Performance Unit Plan. Performance units earned as of December 31, 2014 and 2013, vested and were settled during the first quarter of 2015 and 2014 , and had a total intrinsic value of $13.2 million and $14.8 million , respectively. The actual tax benefit realized for the tax deductions from the settlement of performance units was approximately $4.8 million and $5.3 million , respectively. As of September 30, 2015 , total compensation cost related to performance units not yet recognized was approximately $21.8 million , which is expected to be recognized over the next 21 months on a weighted-average basis. Restrictions Our ability as a holding company to pay common stock dividends primarily depends on the availability of funds received from our utility subsidiaries and our non-utility subsidiary, W.E. Power, LLC (We Power). Various financing arrangements and regulatory requirements impose certain restrictions on the ability of our subsidiaries to transfer funds to us in the form of cash dividends, loans, or advances. All of our utility subsidiaries, with the exception of Michigan Gas Utilities Corporation (MGU), are prohibited from loaning funds to us, either directly or indirectly. The PSCW allows WPS to pay dividends on its common stock of no more than 103% of the previous year’s common stock dividend. WPS may return capital to us if its average financial debt to common equity ratio is at least 51% on a calendar-year basis. WPS must obtain PSCW approval if a return of capital would cause its average financial common equity ratio to fall below this level. Our right to receive dividends on the common stock of WPS is also subject to the prior rights of WPS's preferred shareholders and to provisions in WPS's restated articles of incorporation, which limit the amount of common stock dividends that WPS may pay if its common stock and common stock surplus accounts constitute less than 25% of its total capitalization. Integrys has short-term and long-term debt obligations that contain financial and other covenants, including, but not limited to, a requirement to maintain a debt to total capitalization ratio not to exceed 65% . NSG's long-term debt obligations contain provisions and covenants restricting the payment of cash dividends and the purchase or redemption of its capital stock. PGL and WPS have short-term debt obligations containing financial and other covenants, including, but not limited to, a requirement to maintain a debt to total capitalization ratio not to exceed 65% . See Note H, Common Equity, in our 2014 Annual Report on Form 10-K for additional information on restrictions at our other subsidiaries. We do not believe that these restrictions will materially affect our operations or limit any dividend payments in the foreseeable future. Share Repurchase Program In December 2013, our Board of Directors authorized a share repurchase program for the purchase of up to $300 million of our common stock through open market purchases or privately negotiated transactions from January 1, 2014, through the end of 2017. On June 22, 2014, in connection with entering into the Merger Agreement, the Board of Directors terminated this share repurchase program. In addition, we have instructed our independent agents to purchase shares on the open market to fulfill exercised stock options and restricted stock awards. The following table identifies shares purchased in the following periods: Nine Months Ended September 30 2015 2014 (in millions) Shares Cost Shares Cost Under share repurchase program — $ — 0.4 $ 18.6 To fulfill exercised stock options and restricted stock awards 1.3 66.1 1.5 65.6 Total 1.3 $ 66.1 1.9 $ 84.2 Integrys Acquisition On June 29, 2015 , we issued approximately 90.2 million common shares to acquire Integrys. All Integrys unvested stock-based compensation awards became fully vested upon the close of the transaction and were paid to award recipients in cash or deferred into a deferred compensation plan. In addition, all vested but unexercised Integrys stock options were paid in cash. See Note 2, Acquisition, for more information on this acquisition. Common Stock Dividends During the quarter ended June 30, 2015, our Board of Directors declared common stock dividends which are summarized below: Date Declared Date Payable Per Share Period April 16, 2015 June 1, 2015 $0.4225 Second Quarter June 12, 2015 July 6, 2015 $0.2067 45 days through June 28, 2015 June 12, 2015 September 1, 2015 $0.2337 47 days through Aug. 14, 2015 Pro rata dividends were declared on June 12, 2015 in anticipation of the acquisition of Integrys. The dividend payable on July 6, 2015, was based on a quarterly rate of $0.4225 per share. Pursuant to the terms of the Merger Agreement, our Board of Directors adopted a new dividend policy. The dividend payable on September 1, 2015, was based on our new quarterly rate of $0.4575 per share, which represents an 8.3% increase over the prior quarterly rate.

Short-term Debt and Lines of Cr

Short-term Debt and Lines of Credit	9 Months Ended
	Sep. 30, 2015
Short-term Debt [Abstract]
Short-term Debt and Lines of Credit	SHORT-TERM DEBT AND LINES OF CREDIT Our outstanding short-term borrowings were as follows: (in millions, except percentages) September 30, 2015 December 31, 2014 Commercial paper $ 661.5 $ 617.6 Weighted-average interest rate on commercial paper outstanding 0.32 % 0.22 % Our average amount of commercial paper borrowings based on daily outstanding balances during the nine months ended September 30, 2015, was $785.6 million with a weighted-average interest rate during the period of 0.27% . We manage our liquidity by maintaining what we believe to be adequate external financing commitments. The information in the table below relates to our revolving credit facilities used to support our commercial paper borrowing program, including remaining available capacity under these facilities: (in millions) Maturity September 30, 2015 WEC Energy Group December 2019 $ 400.0 Wisconsin Electric December 2019 500.0 Wisconsin Gas December 2019 350.0 Integrys June 2017 285.0 Integrys May 2019 265.0 WPS May 2019 135.0 WPS June 2017 115.0 PGL June 2017 250.0 Total short-term credit capacity $ 2,300.0 Less: Letters of credit issued inside credit facilities $ 18.0 Commercial paper outstanding 661.5 Available capacity under existing agreements $ 1,620.5

Long Term Debt

Long Term Debt	9 Months Ended
	Sep. 30, 2015
Long-term Debt, Unclassified [Abstract]
Long Term Debt	LONG-TERM DEBT Our outstanding long-term debt, including current maturities as of September 30, 2015 , included approximately $3.0 billion of Integrys debt assumed on June 29, 2015. The amount assumed included $46.2 million of fair value adjustments recorded in connection with purchase accounting, which will be amortized over the estimated remaining life of the debt and will not be a part of future principal payments. See Note 2, Acquisition, for more information regarding the acquisition. On September 30, 2015 , Wisconsin Gas issued $200.0 million of 3.53% Debentures due September 30, 2025. The net proceeds were used to repay short-term debt and for general corporate purposes. On August 1, 2015, the interest rate on PGL's $50.0 million of 2.625% Series WW Bonds was reset. The new interest rate is 1.875% . The new mandatory interest reset date is August 1, 2020. The final maturity of these bonds is February 1, 2033. In July 2015, Integrys tendered an offer to repurchase all $55.0 million outstanding of its 8.00% Senior Notes due June 1, 2016, and $5.0 million of this amount was tendered and purchased. The $50.0 million balance of these notes was included in the current portion of long-term debt on our balance sheet at September 30, 2015 . In June 2015, WEC Energy Group issued $300.0 million of 1.65% Senior Notes due June 15, 2018, $400.0 million of 2.45% Senior Notes due June 15, 2020, and $500.0 million of 3.55% Senior Notes due June 15, 2025. The net proceeds were used to pay a portion of the cash consideration for the acquisition of Integrys and related transaction costs, and for general corporate purposes. In May 2015, Wisconsin Electric issued $250.0 million of 3.10% Debentures due June 1, 2025. The net proceeds were used to repay short-term debt and for general corporate purposes. In May 2014, Wisconsin Electric issued $250.0 million of 4.25% Debentures due June 1, 2044. The net proceeds were used to repay short-term debt and for general corporate purposes. On April 1, 2014, Wisconsin Electric used short-term borrowings to retire $300.0 million of long-term debt that matured.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2015
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Our inventory consisted of: (in millions) September 30, 2015 December 31, 2014 Materials, supplies, and inventories Natural gas in storage $ 310.3 $ 124.8 Materials and supplies 226.7 150.2 Fossil fuel 182.8 125.6 Total $ 719.8 $ 400.6 PGL and NSG price natural gas storage injections at the calendar year average of the cost of natural gas supply purchased. Withdrawals from storage are priced on the Last-In, First-Out (LIFO) cost method. For interim periods, the difference between current projected replacement cost and the LIFO cost for quantities of natural gas temporarily withdrawn from storage is recorded as a temporary LIFO liquidation debit or credit. At September 30, 2015 , all LIFO layers were replenished, and the LIFO liquidation balance was zero . Substantially all other natural gas in storage, materials and supplies, and fossil fuel inventories are recorded using the weighted-average cost method of accounting.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS 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). Fair value accounting rules provide a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are defined as follows: Level 1 – Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 – Pricing inputs are observable, either directly or indirectly, but are not quoted prices included within Level 1. Level 2 includes those financial instruments that are valued using external inputs within models or other valuation methods. Level 3 – Pricing inputs include significant inputs that are generally less observable from objective sources. These inputs may be used with internally developed methods that result in management's best estimate of fair value. Level 3 instruments include those that may be more structured or otherwise tailored to customers' needs. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. We use a mid-market pricing convention (the mid-point price between bid and ask prices) as a practical measure for valuing certain derivative assets and liabilities. We primarily use a market approach for recurring fair value measurements and attempt to use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. When possible, we base the valuations of our risk management assets and liabilities on quoted prices for identical assets and liabilities in active markets. These valuations are classified in Level 1. The valuations of certain contracts not classified as Level 1 may be based on quoted market prices received from counterparties and/or observable inputs for similar instruments. Transactions valued using these inputs are classified in Level 2. Certain derivatives are categorized in Level 3 due to the significance of unobservable or internally-developed inputs. The following tables summarize our financial assets and liabilities that were accounted for at fair value on a recurring basis, categorized by level within the fair value hierarchy: As of September 30, 2015 (in millions) Level 1 Level 2 Level 3 Total Assets Derivative Assets Natural gas contracts $ 2.6 $ 3.9 $ — $ 6.5 Financial transmission rights (FTRs) — — 5.8 5.8 Petroleum product contracts 0.4 — — 0.4 Coal contracts — 0.8 — 0.8 Total Derivative Assets $ 3.0 $ 4.7 $ 5.8 $ 13.5 Investment in exchange-traded funds * $ 49.6 $ — $ — $ 49.6 Liabilities Derivative Liabilities Natural gas contracts $ 15.0 $ 21.5 $ — $ 36.5 Petroleum product contracts 2.1 — — 2.1 Coal contracts — 2.5 5.4 7.9 Total Derivative Liabilities $ 17.1 $ 24.0 $ 5.4 $ 46.5 * Exchange-traded funds are held in the Integrys rabbi trust. The Integrys rabbi trust is an irrevocable trust used to fund participants' benefits under the Integrys deferred compensation program and certain Integrys nonqualified pension plans. As of December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Assets Derivative Assets Natural gas contracts $ 1.1 $ 3.9 $ — $ 5.0 FTRs — — 7.0 7.0 Coal contracts — 3.3 — 3.3 Total Derivative Assets $ 1.1 $ 7.2 $ 7.0 $ 15.3 Liabilities Derivative Liabilities Natural gas contracts $ 11.5 $ 0.8 $ — $ 12.3 Coal contracts — 0.2 — 0.2 Total Derivative Liabilities $ 11.5 $ 1.0 $ — $ 12.5 The derivative assets and liabilities listed in the tables above include options, swaps, futures, physical commodity contracts, and other instruments used to manage market risks related to changes in commodity prices. They also include FTRs, which are used to manage electric transmission congestion costs in the Midcontinent Independent System Operator, Inc. (MISO) market. The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy: Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Balance at the beginning of the period $ 2.3 $ 14.1 $ 7.0 $ 3.5 Realized and unrealized gains 0.2 — 0.2 — Purchases — — 3.9 15.6 Settlements (2.1 ) (4.0 ) (9.4 ) (9.0 ) Acquisition of Integrys — — (1.3 ) — Balance at the end of the period $ 0.4 $ 10.1 $ 0.4 $ 10.1 Unrealized gains and losses on Level 3 derivatives are deferred as regulatory assets or liabilities. Therefore, these fair value measurements have no impact on earnings. Realized gains and losses on these instruments flow through cost of sales on the condensed consolidated income statements. Fair Value of Financial Instruments The following table shows the financial instruments included on our condensed consolidated balance sheets that are not recorded at fair value: September 30, 2015 December 31, 2014 (in millions) Carrying Amount Fair Value Carrying Amount Fair Value Preferred stock $ 81.5 $ 78.8 $ 30.4 $ 27.1 Long-term debt, including current portion $ 9,300.7 $ 9,386.4 $ 4,552.4 $ 5,126.0 Due to the short-term nature of cash and cash equivalents, net accounts receivable, accounts payable, and short-term borrowings, the carrying amount of each such item approximates fair value. The fair value of our preferred stock is estimated based on the quoted market value for the same issue, similar issues, or by using a perpetual dividend discount model. The fair value of our long-term debt, including the current portion of long-term debt, but excluding capitalized leases and unamortized discount on debt, is estimated based upon the quoted market value for the same issue, similar issues, or upon the quoted market prices of U.S. Treasury issues having a similar term to maturity, adjusted for the issuing company's bond rating and the present value of future cash flows.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS We use derivatives as part of our risk management program to manage the risks associated with the price volatility of purchased power, generation, and natural gas costs for the benefit of our customers and shareholders. Our approach is non-speculative and designed to mitigate risk. Regulated hedging programs are approved by our state regulators. We record derivative instruments on the balance sheet as an asset or liability measured at fair value. Changes in the derivative's fair value are recognized currently in earnings unless specific hedge accounting criteria are met or we receive regulatory treatment for the derivative. For most energy-related physical and financial contracts in our regulated operations that qualify as derivatives, our regulators allow the effects of fair value accounting to be offset to regulatory assets and liabilities. The following table shows our derivative assets and derivative liabilities: September 30, 2015 December 31, 2014 (in millions) Balance Sheet Presentation Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Natural gas Other current $ 6.1 $ 33.0 $ 5.0 $ 11.5 Natural gas Other long-term 0.4 3.5 — 0.8 Petroleum products Other current 0.2 1.7 — — Petroleum products Other long-term 0.2 0.4 — — FTRs Other current 5.8 — 7.0 — Coal Other current 0.8 5.2 2.7 0.2 Coal Other long-term — 2.7 0.6 — Other current 12.9 39.9 14.7 11.7 Other long-term 0.6 6.6 0.6 0.8 Total $ 13.5 $ 46.5 $ 15.3 $ 12.5 Gains (losses) on derivative instruments are primarily included in cost of sales on the condensed consolidated income statements. Our estimated notional sales volumes and gains (losses) were as follows: Three Months Ended September 30, 2015 Three Months Ended September 30, 2014 (in millions) Volume Gains (Losses) Volume Gains (Losses) Natural gas 24.2 Dth $ (13.2 ) 6.3 Dth $ (0.8 ) Petroleum products 2.8 gallons (0.9 ) 2.6 gallons — FTRs 8.6 MWh 3.1 6.6 MWh 2.0 Total $ (11.0 ) $ 1.2 Nine Months Ended September 30, 2015 Nine Months Ended September 30, 2014 (in millions) Volume Gains (Losses) Volume Gains Natural gas 47.5 Dth $ (26.2 ) 31.1 Dth $ 9.3 Petroleum products 4.5 gallons (0.9 ) 7.0 gallons 0.6 FTRs 20.7 MWh 6.0 19.7 MWh 11.6 Total $ (21.1 ) $ 21.5 The amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral are not offset against the fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. At September 30, 2015 , and December 31, 2014 , we had posted collateral of $35.7 million and $11.2 million , respectively, in our margin accounts. These amounts were recorded on the condensed consolidated balance sheets in other current assets. The following table shows derivative assets and derivative liabilities if derivative instruments by counterparty were presented net on the condensed consolidated balance sheet: September 30, 2015 December 31, 2014 Derivative Derivative Derivative Derivative (in millions) Assets Liabilities Assets Liabilities Gross amount recognized on the balance sheet $ 13.5 $ 46.5 $ 15.3 $ 12.5 Gross amount not offset on balance sheet * (5.0 ) (19.2 ) (0.4 ) (11.5 ) Net Amount $ 8.5 $ 27.3 $ 14.9 $ 1.0 * Includes cash collateral posted of $14.2 million and $10.3 million as of September 30, 2015 , and December 31, 2014 , respectively. Certain of our derivative and nonderivative commodity instruments contain provisions that could require "adequate assurance" in the event of a material change in our creditworthiness, or the posting of additional collateral for instruments in net liability positions, if triggered by a decrease in credit ratings. The aggregate fair value of all derivative instruments with specific credit risk-related contingent features that were in a liability position was $20.9 million at September 30, 2015 , and zero at December 31, 2014 . At September 30, 2015 , and December 31, 2014 , we had not posted any cash collateral related to the credit risk-related contingent features of these commodity instruments. If all of the credit risk-related contingent features contained in commodity instruments (including derivatives, nonderivatives, normal purchase and normal sales contracts, and applicable payables and receivables) had been triggered at September 30, 2015 , we would have been required to post collateral of $19.6 million . No collateral would have been required at December 31, 2014. During the second quarter of 2015, we settled several forward interest rate swap agreements entered into earlier in the quarter to mitigate interest risk associated with the issuance of $1.2 billion of long-term debt related to the acquisition of Integrys. As these agreements qualified for cash flow hedging accounting treatment, the payments of $19.0 million received upon settlement of these agreements were deferred in accumulated other comprehensive income and are being amortized as a decrease to interest expense over the periods in which the interest costs are recognized in earnings. During the nine months ended September 30, 2015 , we reclassified $0.4 million of forward interest rate swap agreement settlements deferred in accumulated other comprehensive income as a reduction to interest expense. We estimate that during the next twelve months, $1.3 million will be reclassified from accumulated other comprehensive income as a reduction to interest expense.

Guarantees

Guarantees	9 Months Ended
	Sep. 30, 2015
Guarantees [Abstract]
GUARANTEES	GUARANTEES The following table shows our outstanding guarantees: Total Amounts Committed Expiration (in millions) at September 30, 2015 Less Than 1 Year 1 to 3 Years Over 3 Years Guarantees Guarantees supporting commodity transactions of subsidiaries (1) $ 161.4 $ 89.4 $ — $ 72.0 Standby letters of credit (2) 28.6 28.5 0.1 — Surety bonds (3) 36.6 36.6 — — Other guarantees (4) 71.2 20.7 0.1 50.4 Total guarantees $ 297.8 $ 175.2 $ 0.2 $ 122.4 (1) Consists of (a) $5.0 million and $6.0 million to support the business operations of WEC Business Services, LLC (WBS) and WPS Power Development, LLC (PDL), respectively; and, (b) $0.9 million , $113.8 million and $35.7 million related to natural gas supply at ITF, Minnesota Energy Resources Corporation (MERC) and MGU, respectively. These guarantees are not reflected on our condensed consolidated balance sheets. (2) At our request or the request of our subsidiaries, financial institutions have issued standby letters of credit for the benefit of third parties that have extended credit to our subsidiaries. These amounts are not reflected on our condensed consolidated balance sheets. (3) Primarily for the construction and operation of CNG fueling stations by ITF, workers compensation self-insurance programs, and obtaining various licenses, permits and rights-of-way. These amounts are not reflected on our condensed consolidated balance sheets. (4) Consists of (a) $19.1 million to support PDL's future payment obligations related to its distributed solar generation projects, of which $6.6 million is covered by a reciprocal guarantee from a third party; (b) $20.0 million for an interconnection agreement between WPS and ATC; (c) $10.0 million related to the sale of a nonregulated retail marketing business previously owned by Integrys; (d) $11.2 million related to the performance of an operating and maintenance agreement by ITF; and (e) $10.9 million related to other indemnifications. The amounts discussed in items (a), (b) and (d) are not reflected on our condensed consolidated balance sheets. An insignificant liability was recorded for item (c) related to the possible imposition of additional miscellaneous gross receipts tax in the event of a change in law or interpretation of the law. In addition, a liability of $10.2 million related to workers compensation coverage was recorded for item (e).

Employee Benefits

Employee Benefits	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
EMPLOYEE BENEFITS	EMPLOYEE BENEFITS Defined Benefit Plans The following tables show the components of net periodic pension and other postretirement employee benefits (OPEB) costs for our benefit plans. Our pension and OPEB costs for the three and nine months ended September 30, 2015, include costs attributable to the Integrys pension and OPEB plans that were incurred subsequent to the acquisition of Integrys on June 29, 2015. The terms and conditions of the legacy company plans have not changed since the acquisition. Pension Costs Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Service cost $ 11.3 $ 2.6 $ 19.1 $ 7.6 Interest cost 31.9 17.0 62.2 51.1 Expected return on plan assets (52.1 ) (24.7 ) (103.5 ) (74.0 ) Amortization of: Prior service cost 0.7 0.6 1.7 1.6 Net actuarial loss 22.7 9.1 45.7 27.5 Net periodic benefit cost $ 14.5 $ 4.6 $ 25.2 $ 13.8 OPEB Costs Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Service cost $ 8.0 $ 2.1 $ 12.7 $ 6.4 Interest cost 9.3 4.4 17.4 13.3 Expected return on plan assets (13.9 ) (5.9 ) (25.7 ) (17.8 ) Amortization of: Prior service credit (2.9 ) (0.4 ) (3.5 ) (1.3 ) Net actuarial loss 1.5 0.3 2.5 0.9 Net periodic benefit cost $ 2.0 $ 0.5 $ 3.4 $ 1.5 We contributed $100.0 million to our qualified pension plan during the first nine months of 2015 . No such contribution was made during the first nine months of 2014 .

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS The following table shows changes to the carrying amount of our goodwill. There were no impairments recorded in 2015. We have not yet completed the allocation of goodwill to our business segments for the acquisition of Integrys, but we plan to complete it during 2015. (in millions) Goodwill balance at December 31, 2014 $ 441.9 Acquisition of Integrys * 2,947.2 Goodwill balance at September 30, 2015 $ 3,389.1 * See Note 2, Acquisition, for more information . The identifiable intangible assets other than goodwill listed below are part of other long-term assets on the balance sheets. We had no material intangible assets other than goodwill at December 31, 2014. September 30, 2015 (in millions) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortized intangible assets (1) $ 16.0 $ (7.0 ) $ 9.0 Unamortized intangible assets (2) 5.7 — 5.7 Total intangible assets $ 21.7 $ (7.0 ) $ 14.7 (1) Primarily relates to contractual service agreements that provide for major maintenance and protection against unforeseen maintenance costs related to the combustion turbine generators at WPS's Fox Energy Center. The remaining weighted-average amortization period for our amortized intangible assets at September 30, 2015 , was approximately three years . (2) Consists primarily of a trade name.

Investment in ATC

Investment in ATC	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENT IN ATC	INVESTMENT IN ATC Due to the acquisition of Integrys on June 29, 2015, our ownership of ATC increased from 26.2% to approximately 60% . ATC is a for-profit, transmission-only company regulated by the FERC. The following table shows changes to our investment in ATC: Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Balance at beginning of period $ 987.8 $ 416.8 $ 424.1 $ 402.7 Add: Earnings from equity method investment 40.0 18.0 70.4 52.8 Add: Capital contributions 3.0 2.6 5.5 10.4 Add: Acquisition of Integrys's investment in ATC — — 552.0 — Less: Distributions received 31.4 14.1 52.6 42.6 Balance at end of period $ 999.4 $ 423.3 $ 999.4 $ 423.3 Summarized financial data for ATC is included in the following tables: Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Income statement data Revenues $ 164.5 $ 163.7 $ 482.0 $ 487.0 Operating expenses 78.0 76.6 238.3 229.6 Other expense 23.1 21.6 71.7 65.1 Net income $ 63.4 $ 65.5 $ 172.0 $ 192.3 (in millions) September 30, 2015 December 31, 2014 Balance sheet data Current assets $ 80.8 $ 66.4 Noncurrent assets 3,900.9 3,728.7 Total assets $ 3,981.7 $ 3,795.1 Current liabilities $ 294.8 $ 313.1 Long-term debt 1,800.0 1,701.0 Other noncurrent liabilities 207.1 163.8 Shareholders' equity 1,679.8 1,617.2 Total liabilities and shareholders' equity $ 3,981.7 $ 3,795.1

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Information [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION We reorganized our business segments during the third quarter of 2015 to reflect our new internal organization and management structure following the acquisition of Integrys. We use operating income to measure segment profitability and allocate resources to our businesses. All prior period amounts impacted by this change were reclassified to conform to the new presentation. At September 30, 2015 , we reported six segments, which are described below. • The Wisconsin segment includes the electric and natural gas utility and nonutility operations of Wisconsin Electric, Wisconsin Gas, and WPS, including Wisconsin Electric's and WPS's electric and natural gas operations in the state of Michigan. • The Illinois segment includes the natural gas utility and nonutility operations of NSG and PGL. • The Other States segment includes the natural gas utility and nonutility operations of MERC and MGU. • The Electric Transmission segment includes our approximate 60% ownership interest in ATC, a federally regulated electric transmission company. • We Power is our non-regulated entity that owns and leases generating facilities to Wisconsin Electric. • The Corporate and Other segment includes all other nonutility activities of the holding company, Wispark LLC, Bostco LLC, Wisconsin Energy Capital Corporation (WECC), ITF, PDL, Integrys, Peoples Energy, LLC holding company, and WBS. Summarized financial information concerning our reportable segments for the three and nine months ended September 30, 2015 and 2014 , is shown in the following tables: Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Three Months Ended September 30, 2015 Operating revenues $ 1,442.3 $ 171.8 $ 49.6 $ — $ 1,663.7 $ 110.7 $ 27.9 $ (103.6 ) $ 1,698.7 Other operation and maintenance 501.9 101.0 23.1 — 626.0 0.6 12.9 (103.6 ) 535.9 Depreciation and amortization 117.5 31.2 4.9 — 153.6 16.9 6.0 — 176.5 Operating income (loss) 256.6 3.5 (3.7 ) — 256.4 93.2 (3.9 ) — 345.7 Equity in earnings of unconsolidated affiliates 0.2 — — 40.0 40.2 — (0.3 ) 0.1 40.0 Interest expense 46.5 9.7 2.6 — 58.8 15.8 31.6 (2.4 ) 103.8 Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Three Months Ended September 30, 2014 Operating revenues $ 1,017.7 $ — $ — $ — $ 1,017.7 $ 109.0 $ 5.3 $ (98.7 ) $ 1,033.3 Other operation and maintenance 337.4 — — — 337.4 0.4 9.0 (97.4 ) 249.4 Depreciation and amortization 82.8 — — — 82.8 16.7 0.4 (0.1 ) 99.8 Operating income (loss) 158.4 — — — 158.4 92.0 (4.3 ) — 246.1 Equity in earnings of unconsolidated affiliates — — — 18.0 18.0 — — — 18.0 Interest expense 32.1 — — — 32.1 16.1 12.4 (0.2 ) 60.4 Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Nine Months Ended September 30, 2015 Operating revenues $ 3,799.1 $ 171.8 $ 49.6 $ — $ 4,020.5 $ 333.1 $ 31.3 $ (307.1 ) $ 4,077.8 Other operation and maintenance 1,239.3 101.0 23.1 — 1,363.4 3.7 93.1 (306.6 ) 1,153.6 Depreciation and amortization 289.2 31.2 4.9 — 325.3 50.6 6.8 (0.1 ) 382.6 Operating income (loss) 673.5 3.5 (3.7 ) — 673.3 278.9 (81.9 ) — 870.3 Equity in earnings of unconsolidated affiliates 0.2 — — 70.4 70.6 — (0.4 ) 0.2 70.4 Interest expense 110.6 9.7 2.6 — 122.9 47.6 57.5 (2.4 ) 225.6 Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Nine Months Ended September 30, 2014 Operating revenues $ 3,729.6 $ — $ — $ — $ 3,729.6 $ 328.1 $ 8.6 $ (294.3 ) $ 3,772.0 Other operation and maintenance 1,048.6 — — — 1,048.6 3.6 19.1 (290.5 ) 780.8 Depreciation and amortization 244.1 — — — 244.1 49.9 1.2 — 295.2 Operating income (loss) 606.3 — — — 606.3 274.6 (12.3 ) — 868.6 Equity in earnings of unconsolidated affiliates — — — 52.8 52.8 — — — 52.8 Interest expense 96.8 — — — 96.8 48.6 36.8 (0.5 ) 181.7

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2015
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Determination Methodology and Factors [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIES The primary beneficiary of a variable interest entity must consolidate the entity's assets and liabilities. In addition, certain disclosures are required for significant interest holders in variable interest entities. We assess our relationships with potential variable interest entities, such as our coal suppliers, natural gas suppliers, coal and natural gas transporters, and other counterparties related to power purchase agreements, investments, and joint ventures. In making this assessment, we consider, along with other factors, the potential that our contracts or other arrangements provide subordinated financial support, the obligation to absorb the entity's losses, the right to receive residual returns of the entity, and the power to direct the activities that most significantly impact the entity's economic performance. Purchased Power Agreement We have identified a purchased power agreement that represents a variable interest. This agreement is for 236 MW of firm capacity from a natural gas-fired cogeneration facility, and we account for it as a capital lease. The agreement includes no minimum energy requirements over the remaining term of approximately 7 years . We have examined the risks of the entity, including operations and maintenance, dispatch, financing, fuel costs and other factors, and have determined that we are not the primary beneficiary of the entity. We do not hold an equity or debt interest in the entity, and there is no residual guarantee associated with the purchased power agreement. We have approximately $141.3 million of required payments over the remaining term of this agreement. We believe that the required lease payments under this contract will continue to be recoverable in rates. Total capacity and lease payments under this contract for the nine months ended September 30, 2015 , and September 30, 2014 , were $40.2 million and $39.8 million , respectively. Our maximum exposure to loss is limited to the capacity payments under the contract. ATC We own approximately 60% of ATC, a for-profit, transmission-only company regulated by the FERC. We have determined that ATC is a variable interest entity but that consolidation is not required since we are not ATC's primary beneficiary. As a result of our limited voting rights, we do not have the power to direct the activities that most significantly impact ATC's economic performance. We instead account for ATC as an equity method investment. See Note 13, Investment in ATC, for more information on ATC. The significant assets and liabilities related to ATC recorded on our balance sheet at September 30, 2015, included our equity investment in this affiliate and accounts payable. At September 30, 2015, our equity investment was $999.4 million , which approximates our maximum exposure to loss as a result of our involvement with ATC. In addition, we had $28.1 million of accounts payable due to ATC for network transmission services at September 30, 2015.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Unconditional Purchase Obligations We and our subsidiaries routinely enter into long-term purchase and sale commitments for various quantities and lengths of time. Our natural gas utilities have obligations to distribute and sell natural gas to their customers, and our electric utilities have obligations to distribute and sell electricity to their customers. The utilities expect to recover costs related to these obligations in future customer rates. Our minimum future commitments related to these purchase obligations as of September 30, 2015, including those of our subsidiaries, was $12,586.8 million . Environmental Matters We periodically review our exposure for environmental remediation costs as evidence becomes available indicating that our liability has changed. Given current information, including the following, we believe that future costs in excess of the amounts accrued and/or disclosed on all presently known and quantifiable environmental contingencies will not be material to our financial position or results of operations. We have a program of comprehensive environmental remediation planning for former manufactured gas plant sites and coal combustion product disposal/landfill sites. We perform ongoing assessments of these sites used by our utilities. Manufactured Gas Plant Remediation We have identified sites at which our utilities or a predecessor company owned or operated a manufactured gas plant or stored manufactured gas. We have also identified other sites that may have been impacted by historical manufactured gas plant activities. Our natural gas utilities are responsible for the environmental remediation of these sites, some of which are in the United States Environmental Protection Agency (EPA) Superfund Program. We are also working with various state jurisdictions in our investigation and remediation planning. All sites are at various stages of investigation, monitoring, remediation, and closure. In addition, certain of our natural gas utilities are coordinating the investigation and cleanup of the sites subject to the jurisdiction of the EPA under what is called a "multisite" program. This program involves prioritizing the work to be done at the sites, preparation and approval of documents common to all of the sites, and use of a consistent approach in selecting remedies. At this time, we cannot estimate future remediation costs associated with these sites beyond those described below. The future costs for detailed site investigation, future remediation, and monitoring are dependent upon several variables including, among other things, the extent of remediation, changes in technology, and changes in regulation. Historically, our regulators have allowed us to recover incurred costs, net of insurance recoveries and recoveries from potentially responsible parties, associated with the remediation of manufactured gas plant sites. Accordingly, we have established regulatory assets for costs associated with these sites. We have established the following regulatory assets and reserves related to manufactured gas plant sites: (in millions) September 30, 2015 December 31, 2014 Regulatory assets $ 676.2 $ 45.9 Reserves for future remediation 611.3 32.6 The increases in the regulatory assets and reserves are primarily related to balances associated with the Integrys regulated companies, which were acquired on June 29, 2015. See Note 2, Acquisition, for more information .

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION Nine Months Ended September 30 (in millions) 2015 2014 Cash paid for interest, net of amount capitalized $ 151.0 $ 143.4 Cash paid for income taxes, net of refunds 2.0 22.0 Significant noncash transactions related to continuing operations: Accounts payable related to construction costs 179.1 4.9 Amortization of deferred revenue 30.3 41.7 At September 30, 2015 , restricted cash of $108.7 million was recorded within other long-term assets on the condensed consolidated balance sheets. This amount was held in the Integrys rabbi trust and represents a portion of the required funding that was triggered by the announcement of the Integrys acquisition.

Michigan Settlement

Michigan Settlement	9 Months Ended
	Sep. 30, 2015
Michigan Settlement [Abstract]
Michigan Settlement Disclosure [Text Block]	MICHIGAN SETTLEMENT In March 2015, we entered into an Amended and Restated Settlement Agreement with the Attorney General of the State of Michigan, the Staff of the MPSC, and Tilden Mining Company and Empire Iron Mining Partnership (Amended Agreement) to resolve all objections to our acquisition of Integrys these parties raised at the MPSC. The agreement includes the following provisions: • The parties to the Amended Agreement agree that the acquisition satisfies the applicable requirements under Michigan law and should be approved by the MPSC. • Wisconsin Electric will not enter into a System Support Resource (SSR) agreement for the operation of Presque Isle Power Plant (PIPP) so long as both mines, if operational, remain full requirements customers of Wisconsin Electric until the earlier of: (a) the date a new, clean generation plant located in the Upper Peninsula of Michigan commences commercial operation; or, (b) December 31, 2019. The prior SSR agreement was terminated effective February 1, 2015, with the return of the mines as full requirements customers. • We commit to invest, either through an ownership interest or a purchased power agreement, or to have, if formed, our future Michigan jurisdictional utility invest in this plant subject to the issuance of a Certificate of Necessity from the MPSC. The costs of this plant would be recovered from Michigan customers. In addition, in March 2015, Wisconsin Electric entered into a special contract with each of the mines to provide full requirements electric service through December 31, 2019. In April 2015, the MPSC approved our acquisition of Integrys, the Amended Agreement, and the special contracts with the two mines.

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted	NEW ACCOUNTING PRONOUNCEMENTS Revenue Recognition In May 2014, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board issued their joint revenue recognition standard, Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers. The guidance is based on the principle that revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This guidance is effective for fiscal years and interim periods beginning after December 15, 2017, with early adoption for fiscal years and interim periods beginning after December 15, 2016, permitted. The standard can either be applied retrospectively or as a cumulative-effect adjustment as of the date of adoption. We are currently assessing the effects this guidance may have on our consolidated financial statements. Debt Issuance Costs In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs. The guidance requires debt issuance costs to be presented on the balance sheet as a reduction to the carrying value of the corresponding debt, rather than as an asset as it is currently presented. This guidance is effective for fiscal years and interim periods beginning after December 15, 2015. The standard requires retrospective application by restating each prior period presented in the financial statements. We are currently assessing the effects this guidance may have on our consolidated financial statements.

General Information (Policies)

General Information (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting policies
Consolidation	As used in these notes, the term "financial statements" refers to the condensed consolidated financial statements. This includes the condensed consolidated income statements, condensed consolidated statements of comprehensive income, condensed consolidated balance sheets, and condensed consolidated statements of cash flows, unless otherwise noted. In this report, when we refer to "the Company," "us," "we," "our," or "ours," we are referring to WEC Energy Group and all of its subsidiaries.
Basis of accounting	We have prepared the unaudited interim financial statements presented in this Form 10-Q pursuant to the rules and regulations of the SEC and United States Generally Accepted Accounting Principles (GAAP). Accordingly, these financial statements do not include all of the information and footnotes required by GAAP for annual financial statements. These financial statements should be read in conjunction with the consolidated financial statements and footnotes in our Annual Report on Form 10-K for the year ended December 31, 2014 . Financial results for an interim period may not give a true indication of results for the year. In particular, the results of operations for the three and nine months ended September 30, 2015 , are not necessarily indicative of expected results for 2015 due to the acquisition of Integrys, seasonal variations, and other factors. In management's opinion, we have included all adjustments, normal and recurring in nature, necessary for a fair presentation of our financial results.
Fair value measurements	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). Fair value accounting rules provide a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The three levels of the fair value hierarchy are defined as follows: Level 1 – Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 – Pricing inputs are observable, either directly or indirectly, but are not quoted prices included within Level 1. Level 2 includes those financial instruments that are valued using external inputs within models or other valuation methods. Level 3 – Pricing inputs include significant inputs that are generally less observable from objective sources. These inputs may be used with internally developed methods that result in management's best estimate of fair value. Level 3 instruments include those that may be more structured or otherwise tailored to customers' needs. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. We use a mid-market pricing convention (the mid-point price between bid and ask prices) as a practical measure for valuing certain derivative assets and liabilities. We primarily use a market approach for recurring fair value measurements and attempt to use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. When possible, we base the valuations of our risk management assets and liabilities on quoted prices for identical assets and liabilities in active markets. These valuations are classified in Level 1. The valuations of certain contracts not classified as Level 1 may be based on quoted market prices received from counterparties and/or observable inputs for similar instruments. Transactions valued using these inputs are classified in Level 2. Certain derivatives are categorized in Level 3 due to the significance of unobservable or internally-developed inputs.
New Accounting Pronouncements	Revenue Recognition In May 2014, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board issued their joint revenue recognition standard, Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers. The guidance is based on the principle that revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This guidance is effective for fiscal years and interim periods beginning after December 15, 2017, with early adoption for fiscal years and interim periods beginning after December 15, 2016, permitted. The standard can either be applied retrospectively or as a cumulative-effect adjustment as of the date of adoption. We are currently assessing the effects this guidance may have on our consolidated financial statements. Debt Issuance Costs In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs. The guidance requires debt issuance costs to be presented on the balance sheet as a reduction to the carrying value of the corresponding debt, rather than as an asset as it is currently presented. This guidance is effective for fiscal years and interim periods beginning after December 15, 2015. The standard requires retrospective application by restating each prior period presented in the financial statements. We are currently assessing the effects this guidance may have on our consolidated financial statements.

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Consideration Transferred	The total consideration transferred was based on the closing price of Wisconsin Energy common stock on June 29, 2015 , and was calculated as follows: Consideration Paid (in millions, except per share amounts) Stock Cash Total Integrys common shares outstanding at June 29, 2015 79,963,091 79,963,091 Exchange ratio 1.128 Wisconsin Energy shares issued for Integrys shares * 90,187,884 Closing price of Wisconsin Energy common shares on June 29, 2015 $45.16 Fair value of common stock issued $ 4,072.9 $ 4,072.9 Cash paid per share of Integrys shares outstanding $18.58 Fair value of cash paid for Integrys shares * $ 1,486.2 $ 1,486.2 Consideration attributable to settlement of equity awards, net of tax $ 24.0 $ 24.0 Total purchase price $ 4,072.9 $ 1,510.2 $ 5,583.1 * Fractional shares of 10,483 totaling $0.5 million were paid in cash.
Allocation of Purchase Price	The preliminary purchase price allocation is as follows: (in millions) Current assets $ 1,178.2 Net property, plant and equipment 7,097.9 Goodwill 2,947.2 Deferred charges and other assets, excluding goodwill 2,393.7 Current liabilities, including current maturities of long-term debt (1,261.3 ) Deferred credits and other liabilities (3,774.0 ) Long-term debt (2,947.5 ) Preferred stock of subsidiary (51.1 ) Total purchase price $ 5,583.1
Pro Forma Financial Information	Three Months Ended September 30 Nine Months Ended September 30 (in millions, except per share amounts) 2015 2014 2015 2014 Unaudited Pro Forma Financial Information Operating Revenues $ 1,698.7 $ 1,689.8 $ 5,878.8 $ 6,898.0 Net Income $ 185.5 $ 210.7 $ 664.9 $ 712.1 Earnings per share (Basic) $ 0.59 $ 0.67 $ 2.11 $ 2.26 Earnings per share (Diluted) $ 0.58 $ 0.66 $ 2.10 $ 2.24

Dispositions (Tables)

Dispositions (Tables)	9 Months Ended
	Sep. 30, 2015
Corporate and Other | ITF
Dispositions
Schedule of assets and liabilities included in held for sale	The following table shows the carrying values of the major classes of assets and liabilities included as held for sale on the balance sheet: (in millions) September 30, 2015 Property, plant and equipment, net of accumulated depreciation of $6.4 $ 46.2 Accounts receivable and unbilled revenues 42.9 Materials, supplies and inventories 16.6 Other current assets 5.1 Other long-term assets 29.4 Total assets $ 140.2 Accounts payable $ 11.9 Accrued payroll and benefits 1.8 Other current liabilities 7.1 Pension and other postretirement benefit obligations 0.4 Other long-term liabilities 0.4 Total liabilities * $ 21.6 * Included in other current liabilities on the balance sheet.

Common Equity (Tables)

Common Equity (Tables)	9 Months Ended
	Sep. 30, 2015
Common Equity (Tables) [Abstract]
Assumptions for valuing options using binomial option pricing model	Nine Months Ended September 30 2015 2014 Non-qualified stock options granted 516,475 899,500 Estimated fair value per non-qualified stock option $ 5.29 $ 4.18 Assumptions used to value the options using a binomial option pricing model: Risk-free interest rate 0.1% – 2.1% 0.1% – 3.0% Dividend yield 3.7 % 3.8 % Expected volatility 18.0 % 18.0 % Expected forfeiture rate 2.0 % 2.0 % Expected life (years) 5.8 5.8
Stock option activity	The following is a summary of our stock option activity for the three and nine months ended September 30, 2015 : Weighted-Average Remaining Aggregate Number of Weighted-Average Contractual Life Intrinsic Value Stock Options Options Exercise Price (in years) (in millions) Outstanding as of July 1, 2015 6,750,930 $ 32.32 Granted — $ — Exercised (599,752 ) $ 23.72 Outstanding as of September 30, 2015 6,151,178 $ 33.16 Outstanding as of January 1, 2015 6,770,194 $ 29.99 Granted 516,475 $ 52.90 Exercised (1,135,491 ) $ 23.25 Outstanding as of September 30, 2015 6,151,178 $ 33.16 5.8 $ 117.2 Exercisable as of September 30, 2015 3,419,728 $ 26.49 4.0 $ 88.0
Restricted stock activity	The following restricted stock activity occurred during the three and nine months ended September 30, 2015 : Weighted-Average Restricted Shares Number of Shares Grant Date Fair Value Outstanding as of July 1, 2015 147,214 $ 45.43 Granted 82,943 $ 49.17 Released — $ — Forfeited (181 ) $ 46.16 Outstanding as of September 30, 2015 229,976 $ 46.78 Outstanding as of January 1, 2015 155,479 $ 38.45 Granted 143,107 $ 51.13 Released (68,429 ) $ 36.95 Forfeited (181 ) $ 46.16 Outstanding as of September 30, 2015 229,976 $ 46.78
Shares Repurchased	The following table identifies shares purchased in the following periods: Nine Months Ended September 30 2015 2014 (in millions) Shares Cost Shares Cost Under share repurchase program — $ — 0.4 $ 18.6 To fulfill exercised stock options and restricted stock awards 1.3 66.1 1.5 65.6 Total 1.3 $ 66.1 1.9 $ 84.2
Dividends Declared	During the quarter ended June 30, 2015, our Board of Directors declared common stock dividends which are summarized below: Date Declared Date Payable Per Share Period April 16, 2015 June 1, 2015 $0.4225 Second Quarter June 12, 2015 July 6, 2015 $0.2067 45 days through June 28, 2015 June 12, 2015 September 1, 2015 $0.2337 47 days through Aug. 14, 2015

Short-term Debt and Lines of 30

Short-term Debt and Lines of Credit (Tables)	9 Months Ended
	Sep. 30, 2015
Short-term Debt [Abstract]
Schedule of short-term borrowings	Our outstanding short-term borrowings were as follows: (in millions, except percentages) September 30, 2015 December 31, 2014 Commercial paper $ 661.5 $ 617.6 Weighted-average interest rate on commercial paper outstanding 0.32 % 0.22 %
Schedule of revolving credit facilities and remaining available capacity	The information in the table below relates to our revolving credit facilities used to support our commercial paper borrowing program, including remaining available capacity under these facilities: (in millions) Maturity September 30, 2015 WEC Energy Group December 2019 $ 400.0 Wisconsin Electric December 2019 500.0 Wisconsin Gas December 2019 350.0 Integrys June 2017 285.0 Integrys May 2019 265.0 WPS May 2019 135.0 WPS June 2017 115.0 PGL June 2017 250.0 Total short-term credit capacity $ 2,300.0 Less: Letters of credit issued inside credit facilities $ 18.0 Commercial paper outstanding 661.5 Available capacity under existing agreements $ 1,620.5

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2015
Inventory Disclosure [Abstract]
Schedule of Inventory, Current [Table Text Block]	Our inventory consisted of: (in millions) September 30, 2015 December 31, 2014 Materials, supplies, and inventories Natural gas in storage $ 310.3 $ 124.8 Materials and supplies 226.7 150.2 Fossil fuel 182.8 125.6 Total $ 719.8 $ 400.6

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair value of assets and liabilities measured on a recurring basis, categorized by level within the fair value hierarchy	The following tables summarize our financial assets and liabilities that were accounted for at fair value on a recurring basis, categorized by level within the fair value hierarchy: As of September 30, 2015 (in millions) Level 1 Level 2 Level 3 Total Assets Derivative Assets Natural gas contracts $ 2.6 $ 3.9 $ — $ 6.5 Financial transmission rights (FTRs) — — 5.8 5.8 Petroleum product contracts 0.4 — — 0.4 Coal contracts — 0.8 — 0.8 Total Derivative Assets $ 3.0 $ 4.7 $ 5.8 $ 13.5 Investment in exchange-traded funds * $ 49.6 $ — $ — $ 49.6 Liabilities Derivative Liabilities Natural gas contracts $ 15.0 $ 21.5 $ — $ 36.5 Petroleum product contracts 2.1 — — 2.1 Coal contracts — 2.5 5.4 7.9 Total Derivative Liabilities $ 17.1 $ 24.0 $ 5.4 $ 46.5 * Exchange-traded funds are held in the Integrys rabbi trust. The Integrys rabbi trust is an irrevocable trust used to fund participants' benefits under the Integrys deferred compensation program and certain Integrys nonqualified pension plans. As of December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Assets Derivative Assets Natural gas contracts $ 1.1 $ 3.9 $ — $ 5.0 FTRs — — 7.0 7.0 Coal contracts — 3.3 — 3.3 Total Derivative Assets $ 1.1 $ 7.2 $ 7.0 $ 15.3 Liabilities Derivative Liabilities Natural gas contracts $ 11.5 $ 0.8 $ — $ 12.3 Coal contracts — 0.2 — 0.2 Total Derivative Liabilities $ 11.5 $ 1.0 $ — $ 12.5
Reconciliation of changes in fair value of items categorized as level 3 measurements	The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy: Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Balance at the beginning of the period $ 2.3 $ 14.1 $ 7.0 $ 3.5 Realized and unrealized gains 0.2 — 0.2 — Purchases — — 3.9 15.6 Settlements (2.1 ) (4.0 ) (9.4 ) (9.0 ) Acquisition of Integrys — — (1.3 ) — Balance at the end of the period $ 0.4 $ 10.1 $ 0.4 $ 10.1
Schedule of carrying value and estimated fair value of financial instruments not recorded at fair value	The following table shows the financial instruments included on our condensed consolidated balance sheets that are not recorded at fair value: September 30, 2015 December 31, 2014 (in millions) Carrying Amount Fair Value Carrying Amount Fair Value Preferred stock $ 81.5 $ 78.8 $ 30.4 $ 27.1 Long-term debt, including current portion $ 9,300.7 $ 9,386.4 $ 4,552.4 $ 5,126.0

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative assets and derivative liabilities	The following table shows our derivative assets and derivative liabilities: September 30, 2015 December 31, 2014 (in millions) Balance Sheet Presentation Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Natural gas Other current $ 6.1 $ 33.0 $ 5.0 $ 11.5 Natural gas Other long-term 0.4 3.5 — 0.8 Petroleum products Other current 0.2 1.7 — — Petroleum products Other long-term 0.2 0.4 — — FTRs Other current 5.8 — 7.0 — Coal Other current 0.8 5.2 2.7 0.2 Coal Other long-term — 2.7 0.6 — Other current 12.9 39.9 14.7 11.7 Other long-term 0.6 6.6 0.6 0.8 Total $ 13.5 $ 46.5 $ 15.3 $ 12.5
Estimated notional volumes and gain (losses)	Our estimated notional sales volumes and gains (losses) were as follows: Three Months Ended September 30, 2015 Three Months Ended September 30, 2014 (in millions) Volume Gains (Losses) Volume Gains (Losses) Natural gas 24.2 Dth $ (13.2 ) 6.3 Dth $ (0.8 ) Petroleum products 2.8 gallons (0.9 ) 2.6 gallons — FTRs 8.6 MWh 3.1 6.6 MWh 2.0 Total $ (11.0 ) $ 1.2 Nine Months Ended September 30, 2015 Nine Months Ended September 30, 2014 (in millions) Volume Gains (Losses) Volume Gains Natural gas 47.5 Dth $ (26.2 ) 31.1 Dth $ 9.3 Petroleum products 4.5 gallons (0.9 ) 7.0 gallons 0.6 FTRs 20.7 MWh 6.0 19.7 MWh 11.6 Total $ (21.1 ) $ 21.5
Offsetting assets and liabilities	The following table shows derivative assets and derivative liabilities if derivative instruments by counterparty were presented net on the condensed consolidated balance sheet: September 30, 2015 December 31, 2014 Derivative Derivative Derivative Derivative (in millions) Assets Liabilities Assets Liabilities Gross amount recognized on the balance sheet $ 13.5 $ 46.5 $ 15.3 $ 12.5 Gross amount not offset on balance sheet * (5.0 ) (19.2 ) (0.4 ) (11.5 ) Net Amount $ 8.5 $ 27.3 $ 14.9 $ 1.0 * Includes cash collateral posted of $14.2 million and $10.3 million as of September 30, 2015 , and December 31, 2014 , respectively.

Guarantees (Tables)

Guarantees (Tables)	9 Months Ended
	Sep. 30, 2015
Guarantees [Abstract]
Schedule of outstanding guarantees	The following table shows our outstanding guarantees: Total Amounts Committed Expiration (in millions) at September 30, 2015 Less Than 1 Year 1 to 3 Years Over 3 Years Guarantees Guarantees supporting commodity transactions of subsidiaries (1) $ 161.4 $ 89.4 $ — $ 72.0 Standby letters of credit (2) 28.6 28.5 0.1 — Surety bonds (3) 36.6 36.6 — — Other guarantees (4) 71.2 20.7 0.1 50.4 Total guarantees $ 297.8 $ 175.2 $ 0.2 $ 122.4 (1) Consists of (a) $5.0 million and $6.0 million to support the business operations of WEC Business Services, LLC (WBS) and WPS Power Development, LLC (PDL), respectively; and, (b) $0.9 million , $113.8 million and $35.7 million related to natural gas supply at ITF, Minnesota Energy Resources Corporation (MERC) and MGU, respectively. These guarantees are not reflected on our condensed consolidated balance sheets. (2) At our request or the request of our subsidiaries, financial institutions have issued standby letters of credit for the benefit of third parties that have extended credit to our subsidiaries. These amounts are not reflected on our condensed consolidated balance sheets. (3) Primarily for the construction and operation of CNG fueling stations by ITF, workers compensation self-insurance programs, and obtaining various licenses, permits and rights-of-way. These amounts are not reflected on our condensed consolidated balance sheets. (4) Consists of (a) $19.1 million to support PDL's future payment obligations related to its distributed solar generation projects, of which $6.6 million is covered by a reciprocal guarantee from a third party; (b) $20.0 million for an interconnection agreement between WPS and ATC; (c) $10.0 million related to the sale of a nonregulated retail marketing business previously owned by Integrys; (d) $11.2 million related to the performance of an operating and maintenance agreement by ITF; and (e) $10.9 million related to other indemnifications. The amounts discussed in items (a), (b) and (d) are not reflected on our condensed consolidated balance sheets. An insignificant liability was recorded for item (c) related to the possible imposition of additional miscellaneous gross receipts tax in the event of a change in law or interpretation of the law. In addition, a liability of $10.2 million related to workers compensation coverage was recorded for item (e).

Employee Benefits (Tables)

Employee Benefits (Tables)	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Schedule of the components of net periodic benefit cost	The following tables show the components of net periodic pension and other postretirement employee benefits (OPEB) costs for our benefit plans. Our pension and OPEB costs for the three and nine months ended September 30, 2015, include costs attributable to the Integrys pension and OPEB plans that were incurred subsequent to the acquisition of Integrys on June 29, 2015. The terms and conditions of the legacy company plans have not changed since the acquisition. Pension Costs Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Service cost $ 11.3 $ 2.6 $ 19.1 $ 7.6 Interest cost 31.9 17.0 62.2 51.1 Expected return on plan assets (52.1 ) (24.7 ) (103.5 ) (74.0 ) Amortization of: Prior service cost 0.7 0.6 1.7 1.6 Net actuarial loss 22.7 9.1 45.7 27.5 Net periodic benefit cost $ 14.5 $ 4.6 $ 25.2 $ 13.8 OPEB Costs Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Service cost $ 8.0 $ 2.1 $ 12.7 $ 6.4 Interest cost 9.3 4.4 17.4 13.3 Expected return on plan assets (13.9 ) (5.9 ) (25.7 ) (17.8 ) Amortization of: Prior service credit (2.9 ) (0.4 ) (3.5 ) (1.3 ) Net actuarial loss 1.5 0.3 2.5 0.9 Net periodic benefit cost $ 2.0 $ 0.5 $ 3.4 $ 1.5

Goodwill and Other Intangible36

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes to the carrying amount of goodwill	The following table shows changes to the carrying amount of our goodwill. There were no impairments recorded in 2015. We have not yet completed the allocation of goodwill to our business segments for the acquisition of Integrys, but we plan to complete it during 2015. (in millions) Goodwill balance at December 31, 2014 $ 441.9 Acquisition of Integrys * 2,947.2 Goodwill balance at September 30, 2015 $ 3,389.1 * See Note 2, Acquisition, for more information .
Schedule of identifiable intangible assets other than goodwill	The identifiable intangible assets other than goodwill listed below are part of other long-term assets on the balance sheets. We had no material intangible assets other than goodwill at December 31, 2014. September 30, 2015 (in millions) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortized intangible assets (1) $ 16.0 $ (7.0 ) $ 9.0 Unamortized intangible assets (2) 5.7 — 5.7 Total intangible assets $ 21.7 $ (7.0 ) $ 14.7 (1) Primarily relates to contractual service agreements that provide for major maintenance and protection against unforeseen maintenance costs related to the combustion turbine generators at WPS's Fox Energy Center. The remaining weighted-average amortization period for our amortized intangible assets at September 30, 2015 , was approximately three years . (2) Consists primarily of a trade name.

Investment in ATC (Tables)

Investment in ATC (Tables) - ATC	9 Months Ended
	Sep. 30, 2015
Investment in ATC
Schedule of changes to our investment in ATC	The following table shows changes to our investment in ATC: Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Balance at beginning of period $ 987.8 $ 416.8 $ 424.1 $ 402.7 Add: Earnings from equity method investment 40.0 18.0 70.4 52.8 Add: Capital contributions 3.0 2.6 5.5 10.4 Add: Acquisition of Integrys's investment in ATC — — 552.0 — Less: Distributions received 31.4 14.1 52.6 42.6 Balance at end of period $ 999.4 $ 423.3 $ 999.4 $ 423.3
Schedule of summarized income statement data for ATC	Summarized financial data for ATC is included in the following tables: Three Months Ended September 30 Nine Months Ended September 30 (in millions) 2015 2014 2015 2014 Income statement data Revenues $ 164.5 $ 163.7 $ 482.0 $ 487.0 Operating expenses 78.0 76.6 238.3 229.6 Other expense 23.1 21.6 71.7 65.1 Net income $ 63.4 $ 65.5 $ 172.0 $ 192.3
Schedule of summarized balance sheet data for ATC	(in millions) September 30, 2015 December 31, 2014 Balance sheet data Current assets $ 80.8 $ 66.4 Noncurrent assets 3,900.9 3,728.7 Total assets $ 3,981.7 $ 3,795.1 Current liabilities $ 294.8 $ 313.1 Long-term debt 1,800.0 1,701.0 Other noncurrent liabilities 207.1 163.8 Shareholders' equity 1,679.8 1,617.2 Total liabilities and shareholders' equity $ 3,981.7 $ 3,795.1

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Information [Abstract]
Financial information of reportable operating segments	Summarized financial information concerning our reportable segments for the three and nine months ended September 30, 2015 and 2014 , is shown in the following tables: Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Three Months Ended September 30, 2015 Operating revenues $ 1,442.3 $ 171.8 $ 49.6 $ — $ 1,663.7 $ 110.7 $ 27.9 $ (103.6 ) $ 1,698.7 Other operation and maintenance 501.9 101.0 23.1 — 626.0 0.6 12.9 (103.6 ) 535.9 Depreciation and amortization 117.5 31.2 4.9 — 153.6 16.9 6.0 — 176.5 Operating income (loss) 256.6 3.5 (3.7 ) — 256.4 93.2 (3.9 ) — 345.7 Equity in earnings of unconsolidated affiliates 0.2 — — 40.0 40.2 — (0.3 ) 0.1 40.0 Interest expense 46.5 9.7 2.6 — 58.8 15.8 31.6 (2.4 ) 103.8 Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Three Months Ended September 30, 2014 Operating revenues $ 1,017.7 $ — $ — $ — $ 1,017.7 $ 109.0 $ 5.3 $ (98.7 ) $ 1,033.3 Other operation and maintenance 337.4 — — — 337.4 0.4 9.0 (97.4 ) 249.4 Depreciation and amortization 82.8 — — — 82.8 16.7 0.4 (0.1 ) 99.8 Operating income (loss) 158.4 — — — 158.4 92.0 (4.3 ) — 246.1 Equity in earnings of unconsolidated affiliates — — — 18.0 18.0 — — — 18.0 Interest expense 32.1 — — — 32.1 16.1 12.4 (0.2 ) 60.4 Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Nine Months Ended September 30, 2015 Operating revenues $ 3,799.1 $ 171.8 $ 49.6 $ — $ 4,020.5 $ 333.1 $ 31.3 $ (307.1 ) $ 4,077.8 Other operation and maintenance 1,239.3 101.0 23.1 — 1,363.4 3.7 93.1 (306.6 ) 1,153.6 Depreciation and amortization 289.2 31.2 4.9 — 325.3 50.6 6.8 (0.1 ) 382.6 Operating income (loss) 673.5 3.5 (3.7 ) — 673.3 278.9 (81.9 ) — 870.3 Equity in earnings of unconsolidated affiliates 0.2 — — 70.4 70.6 — (0.4 ) 0.2 70.4 Interest expense 110.6 9.7 2.6 — 122.9 47.6 57.5 (2.4 ) 225.6 Regulated Operations (in millions) Wisconsin Illinois Other States Electric Transmission Total Regulated Operations We Power Corporate and Other Reconciling Eliminations WEC Energy Group Consolidated Nine Months Ended September 30, 2014 Operating revenues $ 3,729.6 $ — $ — $ — $ 3,729.6 $ 328.1 $ 8.6 $ (294.3 ) $ 3,772.0 Other operation and maintenance 1,048.6 — — — 1,048.6 3.6 19.1 (290.5 ) 780.8 Depreciation and amortization 244.1 — — — 244.1 49.9 1.2 — 295.2 Operating income (loss) 606.3 — — — 606.3 274.6 (12.3 ) — 868.6 Equity in earnings of unconsolidated affiliates — — — 52.8 52.8 — — — 52.8 Interest expense 96.8 — — — 96.8 48.6 36.8 (0.5 ) 181.7

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of regulatory assets and reserves for manufactured gas plant sites	We have established the following regulatory assets and reserves related to manufactured gas plant sites: (in millions) September 30, 2015 December 31, 2014 Regulatory assets $ 676.2 $ 45.9 Reserves for future remediation 611.3 32.6

Supplemental Cash Flow Inform40

Supplemental Cash Flow Information Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	Nine Months Ended September 30 (in millions) 2015 2014 Cash paid for interest, net of amount capitalized $ 151.0 $ 143.4 Cash paid for income taxes, net of refunds 2.0 22.0 Significant noncash transactions related to continuing operations: Accounts payable related to construction costs 179.1 4.9 Amortization of deferred revenue 30.3 41.7

General Information (Details)

General Information (Details)	Sep. 30, 2015	Jun. 29, 2015
General information
Equity method investment, ownership interest (as a percent)		60.00%
ATC
General information
Equity method investment, ownership interest (as a percent)	60.00%	26.20%
Electric
General information
Number of customers	1,600,000
Natural gas
General information
Number of customers	2,800,000

Acquisition Consideration Trans

Acquisition Consideration Transferred (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Jun. 30, 2015	Sep. 30, 2015	Jun. 29, 2015	Dec. 31, 2014
Acquisition
Percentage of Integrys common shares acquired			100.00%
Equity interest in ATC			60.00%
Integrys common shares outstanding at June 29, 2015		315,684,451		225,517,339
Exchange ratio	1.128
Wisconsin Energy Shares issued for Integrys shares	90,187,884
Number of Wisconsin Energy fractional shares that were paid in cash			10,483
Dollar value of Wisconsin Energy fractional shares paid in cash			$ 0.5
Closing price of Wisconsin Energy common shares on June 29, 2015			$ 45.16
Fair value of common stock issued			$ 4,072.9
Cash paid per share of Integrys shares outstanding	$ 18.58
Fair value of cash paid for integrys shares			1,486.2
Consideration attributable to settlement of equity awards, net of tax			24
Total cash consideration paid for acquisition			$ 1,510.2
Total purchase price	$ 5,583.1
Integrys
Acquisition
Equity interest in ATC			34.00%
Integrys common shares outstanding at June 29, 2015			79,963,091

Acquisition Purchase Price Allo

Acquisition Purchase Price Allocation (Details) - USD ($) $ in Millions	1 Months Ended
	Jun. 30, 2015	Jun. 29, 2015
Assets acquired
Current assets		$ 1,178.2
Property, plant and equipment		7,097.9
Goodwill	$ 2,947.2
Other long-term assets, excluding Goodwill		2,393.7
Liabilities assumed
Current liabilities, including current maturities of long-term debt		(1,261.3)
Deferred credits and other liabilities		(3,774)
Long-term debt		(2,947.5)
Preferred stock of subsidiary		$ (51.1)
Acquisition purchase price	$ 5,583.1

Acquisition Approval Conditions

Acquisition Approval Conditions (Details)	1 Months Ended
	Jun. 30, 2015	Jun. 29, 2015
Wisconsin Electric
Acquisition
Duration of earnings cap condition imposed by the PSCW	3 years
ROE in excess of authorized amount		0.005
Wisconsin Gas
Acquisition
Duration of earnings cap condition imposed by the PSCW	3 years
Percentage of first 50 basis points to be shared with customers		50.00%
ROE in excess of authorized amount		0.005
PGL
Acquisition
Duration of rate base freeze condition imposed by the ICC	2 years
NSG
Acquisition
Duration of rate base freeze condition imposed by the ICC	2 years

Acquisition Pro Forma Financial

Acquisition Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Combinations [Abstract]
Operating Revenues	$ 1,698.7	$ 1,689.8	$ 5,878.8	$ 6,898
Net Income	$ 185.5	$ 210.7	$ 664.9	$ 712.1
Earnings per share (Basic)	$ 0.59	$ 0.67	$ 2.11	$ 2.26
Earnings per share (Diluted)	$ 0.58	$ 0.66	$ 2.10	$ 2.24

Acquisition Impacts (Details)

Acquisition Impacts (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 29, 2015
Business Combinations [Abstract]
Equity interest in ATC					60.00%
Acquisition costs	$ 6.5	$ 3.6	$ 80.2	$ 8.6
Revenue attributable to Integrys	633.4			$ 633.4
Net income attributable to Integrys	$ 46.2		$ 19.6

Dispositions (Details)

Dispositions (Details) - Corporate and Other - ITF $ in Millions	Sep. 30, 2015USD ($)
Assets and liabilities included in held for sale
Property, plant, and equipment, net of accumulated depreciation	$ 46.2
Accumulated depreciation	6.4
Accounts receivable and unbilled revenues	42.9
Materials, supplies, and inventories	16.6
Other current assets	5.1
Other long-term assets	29.4
Total assets	140.2
Accounts payable	11.9
Accrued payroll and benefits	1.8
Other current liabilities	7.1
Pension and other postretirement benefit obligations	0.4
Other long-term liabilities	0.4
Total liabilities	$ 21.6

Common Equity - Stock Option Va

Common Equity - Stock Option Valuations (Details) - Employee Stock Option [Member] - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Common Equity 1 [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		516,475
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period	0	516,475	899,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 5.29	$ 4.18
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		3.70%	3.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate		18.00%	18.00%
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Forfeiture Rate		2.00%	2.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term		5 years 10 months	5 years 10 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate		2.10%	3.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate		0.10%	0.10%

Common Equity - Stock Options A

Common Equity - Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Cash received from option exercises			$ 26.4	$ 31.7
Stock options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	6,750,930		6,770,194
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period	0		516,475	899,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(599,752)		(1,135,491)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	6,151,178		6,151,178
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 32.32		$ 29.99
Share Based Compensation Arrangement By Share Based Payment Award Options Grant In Period Weighted Average Exercise Price	0		52.90
Share Based Compensation Arrangement By Share Based Payment Awards Options Exercises In Period Weighted Average Exercise Price	23.72		23.25
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 33.16		$ 33.16
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Period			5 years 9 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 117.2		$ 117.2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	3,419,728		3,419,728
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 26.49		$ 26.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term			4 years
Share Based Compensation Arrangement by Share Based Payments Award, Options Exercisable, Intrinsic Value	$ 88		$ 88
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	15.8	$ 12.7	31.2	$ 30.2
Cash received from option exercises			26.4	31.7
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options			12.5	$ 12.1
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 2.3		$ 2.3
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition			17 months
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			516,475
Exercise price of options that were anti-dilutive	$ 52.90		$ 52.90

Common Equity - Restricted Shar

Common Equity - Restricted Shares (Details) - Restricted stock [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	147,214		155,479
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	82,943		143,107
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	0		(68,429)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(181)		(181)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	229,976		229,976
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 45.43		$ 38.45
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	49.17		51.13
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	0		36.95
Share Based Compensation Arrangement By Share Based Payment Awards Equity Instruments Other Than Options Forfeited In Period Weighted Average Grant Date Fair Value	46.16		46.16
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 46.78		$ 46.78
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 0	$ 0	$ 3.7	$ 2.7
Employee Service Share Based Compensation Tax Benefit Realized from Distribution of Shares	0	$ 0	1.3	$ 1
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 3.8		$ 3.8
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition			22 months

Common Equity - Performance Uni

Common Equity - Performance Units (Details) - Performance Shares [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	195,365	233,735
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 13.2	$ 14.8
Tax Benefit Realized From Payment of Share-Based Liabilities	4.8	$ 5.3
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 21.8
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	21 months

Common Equity - Dividend Restri

Common Equity - Dividend Restrictions (Details)	9 Months Ended
	Sep. 30, 2015
PGL
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio required to be maintained (as a percent)	65.00%
WPS
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio required to be maintained (as a percent)	65.00%
WPS | Maximum [Member] | Public Service Commission of Wisconsin [Member]
Dividend Payment Restrictions [Line Items]
Percentage of previous period's dividend as restriction on current period dividends	103.00%
WPS | Minimum [Member]
Dividend Payment Restrictions [Line Items]
Percentage of common stockholders' equity to total capitalization required to be maintained	25.00%
WPS | Minimum [Member] | Public Service Commission of Wisconsin [Member]
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	51.00%
Integrys
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio required to be maintained (as a percent)	65.00%

Common Equity - Share Repurchas

Common Equity - Share Repurchase Program (Details) - USD ($) shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Class of Stock [Line Items]
Stock Repurchased During Period, Shares	1.3	1.9
Stock Repurchased During Period, Value	$ 66.1	$ 84.2
Share Repurchase Plan, 2013 [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 300
Stock Repurchased During Period, Shares	0	0.4
Stock Repurchased During Period, Value	$ 0	$ 18.6
Share Repurchases to Fulfill Exercised Stock Options and Restricted Stock Awards [Member]
Class of Stock [Line Items]
Stock Repurchased During Period, Shares	1.3	1.5
Stock Repurchased During Period, Value	$ 66.1	$ 65.6

Common Equity - Integrys Acquis

Common Equity - Integrys Acquisition (Details) shares in Millions	1 Months Ended
	Jun. 30, 2015shares
Common Equity 7 [Abstract]
Wisconsin Energy Shares issued for Integrys shares	90.2

Common Equity - Common Stock Di

Common Equity - Common Stock Dividends (Details) - $ / shares	Sep. 01, 2015	Jul. 06, 2015	Jun. 12, 2015	Apr. 16, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Dividends Paid and Payable [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.4575	$ 0			$ 0	$ 0.39	$ 1.29	$ 1.17
Dividend Increase Percentage		8.30%
Dividends declared April 16, 2015, payable June 1, 2015 [Member]
Dividends Paid and Payable [Line Items]
Common Stock, Dividends, Per Share, Declared				$ 0.4225
Dividends declared June 12, 2015, payable July 6, 2015 [Member]
Dividends Paid and Payable [Line Items]
Common Stock, Dividends, Per Share, Declared			$ 0.2067
Dividends declared June 12, 2015, payable September 1, 2015 [Member]
Dividends Paid and Payable [Line Items]
Common Stock, Dividends, Per Share, Declared			$ 0.2337

Short-term Debt and Lines of 56

Short-term Debt and Lines of Credit - Short-term Borrowings (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Short-term borrowings
Commercial Paper	$ 661.5	$ 617.6
Commercial paper
Short-term borrowings
Short-term borrowings outstanding	661.5
Commercial Paper	$ 661.5
Weighted-average interest rate on commercial paper outstanding	0.32%	0.22%
Average amount of commercial paper borrowings outstanding	$ 785.6
Average Interest Rate (as a percent)	0.27%

Short-term Debt and Lines of 57

Short-term Debt and Lines of Credit - Revolving Credit Facilities (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,300
Letters of credit issued inside credit facilities	18
Commercial Paper	661.5	$ 617.6
Available capacity under existing agreements	1,620.5
WEC Energy Group Credit Facility Expiring December 2019 [Member]
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	400
Wisconsin Electric Credit Facility expiring December 2019 [Member]
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	500
Wisconsin Gas Credit facility expiring December 2019 [Member]
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	350
Revolving Credit Facility maturing June 13, 2017 [Member] | Integrys Holding
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	285
Revolving Credit Facility maturing June 13, 2017 [Member] | WPS
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	115
Revolving Credit Facility maturing June 13, 2017 [Member] | PGL
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	250
Revolving credit facility maturing on May 8, 2019 | Integrys Holding
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	265
Revolving credit facility maturing on May 8, 2019 | WPS
Short-term borrowings
Line of Credit Facility, Maximum Borrowing Capacity	135
Commercial paper
Short-term borrowings
Commercial Paper	$ 661.5

Long Term Debt (Details)

Long Term Debt (Details) - USD ($) $ in Millions	Sep. 01, 2015	Jul. 31, 2015	Jun. 30, 2015	May. 31, 2015	May. 31, 2014	Apr. 30, 2014	Sep. 30, 2015	Aug. 01, 2015	Dec. 31, 2014
Long Term Debt (Textuals)
Long-term Debt, Current Maturities							$ 606		$ 424.1
Integrys
Long Term Debt (Textuals)
Long-term Debt Assumed in Business Combination							$ 3,000
Fair Value Adjustment to Long-term Debt			$ 46.2
Integrys | TEG Senior Notes due June 1, 2016 [Member]
Long Term Debt (Textuals)
Offer to buy back $55 million 8% Senior Note		$ 55
Interest rate on long-term debt							8.00%
Long-term Debt, Current Maturities							$ 50
Retirement of long-term debt		$ 5
Wisconsin Gas | Wis Gas Debenture due September 30, 2025 [Member] [Member]
Long Term Debt (Textuals)
Proceeds from Issuance of Debt	$ 200
Interest rate on long-term debt							3.53%
PGL | Fixed First and Refunding Mortgage WW Series 2.625 Percent Bonds, Due 2033 [Member]
Long Term Debt (Textuals)
Interest rate on long-term debt							2.625%	1.875%
Long-term Debt, Gross								$ 50
WEC Energy Group [Domain] | WEC Senior Notes due June 15, 2018 [Member]
Long Term Debt (Textuals)
Proceeds from Issuance of Debt			300
Interest rate on long-term debt							1.65%
WEC Energy Group [Domain] | WEC Senior Notes due June 15, 2020 [Member]
Long Term Debt (Textuals)
Proceeds from Issuance of Debt			400
Interest rate on long-term debt							2.45%
WEC Energy Group [Domain] | WEC Senior Notes due June 15, 2025 [Member]
Long Term Debt (Textuals)
Proceeds from Issuance of Debt			$ 500
Interest rate on long-term debt							3.55%
Wisconsin Electric | Wis Elec Debenture due June 1, 2025 [Member]
Long Term Debt (Textuals)
Proceeds from Issuance of Debt				$ 250
Interest rate on long-term debt				3.10%
Wisconsin Electric | Wis Elec Debenture due June 1, 2044 [Member]
Long Term Debt (Textuals)
Proceeds from Issuance of Debt					$ 250
Interest rate on long-term debt					4.25%
Wisconsin Electric | Wis Elec Debentures due April 1, 2014 [Member]
Long Term Debt (Textuals)
Retirement of long-term debt						$ 300

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Inventory [Line Items]
Natural Gas in Storage	$ 310.3	$ 124.8
Materials and Supplies	226.7	150.2
Fossil Fuel	182.8	125.6
Total	719.8	$ 400.6
PGL and NSG [Member]
Inventory [Line Items]
Temporary LIFO liquidation credit	$ 0

Fair Value Measurements - Asse

Fair Value Measurements - Assets and liabilities measured on a recurring basis (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Assets
Derivative asset	$ 13.5	$ 15.3
Liabilities
Derivative liability	46.5	12.5
Fair value measurements on a recurring basis
Assets
Investment in exchange-traded funds	49.6
Fair value measurements on a recurring basis | Level 1
Assets
Derivative asset	3	1.1
Investment in exchange-traded funds	49.6
Liabilities
Derivative liability	17.1	11.5
Fair value measurements on a recurring basis | Level 2
Assets
Derivative asset	4.7	7.2
Investment in exchange-traded funds	0
Liabilities
Derivative liability	24	1
Fair value measurements on a recurring basis | Level 3
Assets
Derivative asset	5.8	7
Investment in exchange-traded funds	0
Liabilities
Derivative liability	5.4	0
Fair value measurements on a recurring basis | Total
Assets
Derivative asset	13.5	15.3
Liabilities
Derivative liability	46.5	12.5
Fair value measurements on a recurring basis | Natural Gas | Level 1
Assets
Derivative asset	2.6	1.1
Liabilities
Derivative liability	15	11.5
Fair value measurements on a recurring basis | Natural Gas | Level 2
Assets
Derivative asset	3.9	3.9
Liabilities
Derivative liability	21.5	0.8
Fair value measurements on a recurring basis | Natural Gas | Level 3
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0	0
Fair value measurements on a recurring basis | Natural Gas | Total
Assets
Derivative asset	6.5	5
Liabilities
Derivative liability	36.5	12.3
Fair value measurements on a recurring basis | FTRs | Level 1
Assets
Derivative asset	0	0
Fair value measurements on a recurring basis | FTRs | Level 2
Assets
Derivative asset	0	0
Fair value measurements on a recurring basis | FTRs | Level 3
Assets
Derivative asset	5.8	7
Fair value measurements on a recurring basis | FTRs | Total
Assets
Derivative asset	5.8	7
Fair value measurements on a recurring basis | Petroleum products | Level 1
Assets
Derivative asset	0.4
Liabilities
Derivative liability	2.1
Fair value measurements on a recurring basis | Petroleum products | Level 2
Assets
Derivative asset	0
Liabilities
Derivative liability	0
Fair value measurements on a recurring basis | Petroleum products | Level 3
Assets
Derivative asset	0
Liabilities
Derivative liability	0
Fair value measurements on a recurring basis | Petroleum products | Total
Assets
Derivative asset	0.4
Liabilities
Derivative liability	2.1
Fair value measurements on a recurring basis | Coal | Level 1
Assets
Derivative asset	0	0
Liabilities
Derivative liability	0	0
Fair value measurements on a recurring basis | Coal | Level 2
Assets
Derivative asset	0.8	3.3
Liabilities
Derivative liability	2.5	0.2
Fair value measurements on a recurring basis | Coal | Level 3
Assets
Derivative asset	0	0
Liabilities
Derivative liability	5.4	0
Fair value measurements on a recurring basis | Coal | Total
Assets
Derivative asset	0.8	3.3
Liabilities
Derivative liability	$ 7.9	$ 0.2

Fair Value Measurements - Level

Fair Value Measurements - Level 3 Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Changes in the fair value of items measured on a recurring basis and categorized as level 3 measurements
Balance at the beginning of the period	$ 2.3	$ 14.1	$ 7	$ 3.5
Realized and unrealized gains	0.2	0	0.2	0
Purchases	0	0	3.9	15.6
Settlements	(2.1)	(4)	(9.4)	(9)
Acquisition of Integrys	0	0	(1.3)	0
Balance at the end of period	$ 0.4	$ 10.1	$ 0.4	$ 10.1

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments not recorded at fair value (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Financial Instruments
Preferred stock	$ 81.5	$ 30.4
Carrying Value
Financial Instruments
Preferred stock	81.5	30.4
Long-term debt, including current portion	9,300.7	4,552.4
Fair Value
Financial Instruments
Preferred stock	78.8	27.1
Long-term debt, including current portion	$ 9,386.4	$ 5,126

Derivative Instruments - Deriva

Derivative Instruments - Derivative assets and liabilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Derivative Asset
Other current derivative assets	$ 12.9		$ 12.9		$ 14.7
Other long-term derivative assets	0.6		0.6		0.6
Derivative asset	13.5		13.5		15.3
Derivative Liability
Other current derivative liabilities	39.9		39.9		11.7
Other long-term derivative liabilities	6.6		6.6		0.8
Derivative liability	46.5		46.5		12.5
Notional volumes and gains and losses
Gains (losses)	(11)	$ 1.2	(21.1)	$ 21.5
Natural Gas
Derivative Asset
Other current derivative assets	6.1		6.1		5
Other long-term derivative assets	0.4		0.4		0
Derivative Liability
Other current derivative liabilities	33		33		11.5
Other long-term derivative liabilities	$ 3.5		$ 3.5		0.8
Notional volumes and gains and losses
Volume of derivative instruments	24.2 Dth	6.3 Dth	47.5 Dth	31.1 Dth
Gains (losses)	$ (13.2)	$ (0.8)	$ (26.2)	$ 9.3
Petroleum products
Derivative Asset
Other current derivative assets	0.2		0.2		0
Other long-term derivative assets	0.2		0.2		0
Derivative Liability
Other current derivative liabilities	1.7		1.7		0
Other long-term derivative liabilities	$ 0.4		$ 0.4		0
Notional volumes and gains and losses
Volume of derivative instruments	2.8 gallons	2.6 gallons	4.5 gallons	7.0 gallons
Gains (losses)	$ (0.9)	$ 0	$ (0.9)	$ 0.6
FTRs
Derivative Asset
Other current derivative assets	5.8		5.8		7
Derivative Liability
Other current derivative liabilities	$ 0		$ 0		0
Notional volumes and gains and losses
Volume of derivative instruments	8.6 MWh	6.6 MWh	20.7 MWh	19.7 MWh
Gains (losses)	$ 3.1	$ 2	$ 6	$ 11.6
Coal
Derivative Asset
Other current derivative assets	0.8		0.8		2.7
Other long-term derivative assets	0		0		0.6
Derivative Liability
Other current derivative liabilities	5.2		5.2		0.2
Other long-term derivative liabilities	$ 2.7		$ 2.7		$ 0

Derivative Instruments - Offset

Derivative Instruments - Offseting Table (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Gross amount recognized on the balance sheet
Derivative assets and liabilities
Derivative Assets	$ 13.5	$ 15.3
Derivative Liabilities	46.5	12.5
Gross amount not offset on balance sheet
Derivative assets and liabilities
Derivative Assets	(5)	(0.4)
Derivative Liabilities	(19.2)	(11.5)
Cash collateral
Collateral in margin accounts	14.2	10.3
Net Amount
Derivative assets and liabilities
Derivative Assets	8.5	14.9
Derivative Liabilities	$ 27.3	$ 1

Derivative Instruments - Cash C

Derivative Instruments - Cash Collateral and Forward Interest Swap (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
cash collateral and interest rate swap
Derivative, Collateral, Right to Reclaim Cash	$ 35.7	$ 11.2
Aggregate fair value of derivative instruments with credit risk-related contingent features that were in a liability position	20.9	0
Collateral that would have been required	19.6	$ 0
Amount of hedged item deferred into accumulated other comprehensive income	19
Amount of accumulated other comprehensive income reclassified into income	0.4
Amount of accumulated other comprehensive income to be reclassified into income over the next twelve months	1.3
Total senior notes issued in June 2015
cash collateral and interest rate swap
Issuance of long-term debt related to the acquisition of Integrys	$ 1,200

Guarantees (Details)

Guarantees (Details) $ in Millions	Sep. 30, 2015USD ($)
Guarantees
Total guarantees	$ 297.8
Guarantees expiring in less than 1 year	175.2
Guarantees expiring within 1 to 3 years	0.2
Guarantees with expiration over 3 years	122.4
Guarantees supporting commodity transactions of subsidiaries
Guarantees
Total guarantees	161.4
Guarantees expiring in less than 1 year	89.4
Guarantees expiring within 1 to 3 years	0
Guarantees with expiration over 3 years	72
Guarantees supporting commodity transactions of subsidiaries | WBS
Guarantees
Total guarantees	5
Guarantees supporting commodity transactions of subsidiaries | PDL
Guarantees
Total guarantees	6
Guarantees supporting commodity transactions of subsidiaries | ITF
Guarantees
Total guarantees	0.9
Guarantees supporting commodity transactions of subsidiaries | MERC
Guarantees
Total guarantees	113.8
Guarantees supporting commodity transactions of subsidiaries | MGU
Guarantees
Total guarantees	35.7
Standby letters of credit
Guarantees
Total guarantees	28.6
Guarantees expiring in less than 1 year	28.5
Guarantees expiring within 1 to 3 years	0.1
Guarantees with expiration over 3 years	0
Surety bonds
Guarantees
Total guarantees	36.6
Guarantees expiring in less than 1 year	36.6
Guarantees expiring within 1 to 3 years	0
Guarantees with expiration over 3 years	0
Other guarantees
Guarantees
Total guarantees	71.2
Guarantees expiring in less than 1 year	20.7
Guarantees expiring within 1 to 3 years	0.1
Guarantees with expiration over 3 years	50.4
Other guarantees | PDL
Guarantees
Total guarantees	19.1
Other guarantees | ITF
Guarantees
Total guarantees	11.2
Other guarantees | WPS
Guarantees
Total guarantees	20
Other guarantees | Integrys
Guarantees
Total guarantees	10
Reciprocal guarantee | PDL
Guarantees
Total guarantees	6.6
Other indemnifications
Guarantees
Total guarantees	10.9
Liability related to workers compensation coverage	$ 10.2

Employee Benefits (Details)

Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employee Benefit Plans
Pension Contributions			$ 100	$ 0
Pension Benefits
Components of net periodic benefit cost
Service cost	$ 11.3	$ 2.6	19.1	7.6
Interest cost	31.9	17	62.2	51.1
Expected return on plan assets	(52.1)	(24.7)	(103.5)	(74)
Amortization of prior service cost (credit)	0.7	0.6	1.7	1.6
Amortization of net actuarial loss	22.7	9.1	45.7	27.5
Net Periodic Benefit Cost	14.5	4.6	25.2	13.8
Other Postretirement Benefits
Components of net periodic benefit cost
Service cost	8	2.1	12.7	6.4
Interest cost	9.3	4.4	17.4	13.3
Expected return on plan assets	(13.9)	(5.9)	(25.7)	(17.8)
Amortization of prior service cost (credit)	(2.9)	(0.4)	(3.5)	(1.3)
Amortization of net actuarial loss	1.5	0.3	2.5	0.9
Net Periodic Benefit Cost	$ 2	$ 0.5	$ 3.4	$ 1.5

Goodwill and Other Intangible68

Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2015
Goodwill
Goodwill impairment loss		$ 0
Changes to the carrying amount of goodwill
Goodwill balance at December 31, 2014		441.9
Acquisition of Integrys	$ 2,947.2
Goodwill balance at September 30, 2015		3,389.1
Integrys
Changes to the carrying amount of goodwill
Acquisition of Integrys		$ 2,947.2

Goodwill and Other Intangible69

Goodwill and Other Intangible Assets - Intangible Assets Other than Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Intangible assets other than goodwill
Amortized intangible assets, gross carrying amount	$ 16
Amortized intangible assets, accumulated amortization	(7)
Amortized intangible assets, net carrying amount	9
Unamortized intangible assets, carrying amount	5.7
Total intangible assets, gross carrying amount	21.7
Total intangible assets, net carrying amount	$ 14.7	$ 0
Remaining weighted-average amortization period	3 years

Investment in ATC - Changes to

Investment in ATC - Changes to Investment in ATC (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 29, 2015
Investment in ATC
Equity method investment, ownership interest (as a percent)					60.00%
Changes to investment in ATC
Investment in ATC, balance at beginning of period			$ 424.1
Add: Earnings from equity method investment	$ 40	$ 18	70.4	$ 52.8
Investment in ATC, balance at end of period	$ 999.4		$ 999.4
ATC
Investment in ATC
Equity method investment, ownership interest (as a percent)	60.00%		60.00%		26.20%
Changes to investment in ATC
Investment in ATC, balance at beginning of period	$ 987.8	416.8	$ 424.1	402.7
Add: Earnings from equity method investment	40	18	70.4	52.8
Add: Capital contributions	3	2.6	5.5	10.4
Add: Acquisition of Integrys's investment in ATC	0	0	552	0
Less: Distributions received	31.4	14.1	52.6	42.6
Investment in ATC, balance at end of period	$ 999.4	$ 423.3	$ 999.4	$ 423.3

Investment in ATC - ATC Summari

Investment in ATC - ATC Summarized Financial Data (Details) - ATC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Income statement data
Revenues	$ 164.5	$ 163.7	$ 482	$ 487
Operating expenses	78	76.6	238.3	229.6
Other expense	23.1	21.6	71.7	65.1
Net income	63.4	$ 65.5	172	$ 192.3
Balance sheet data
Current assets	80.8		80.8		$ 66.4
Noncurrent assets	3,900.9		3,900.9		3,728.7
Total assets	3,981.7		3,981.7		3,795.1
Current liabilities	294.8		294.8		313.1
Long-term debt	1,800		1,800		1,701
Other noncurrent liabilities	207.1		207.1		163.8
Shareholders' equity	1,679.8		1,679.8		1,617.2
Total liabilities and shareholders' equity	$ 3,981.7		$ 3,981.7		$ 3,795.1

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financial information of reportable operating segments
Operating revenues	$ 1,698.7	$ 1,033.3	$ 4,077.8	$ 3,772
Other operation and maintenance	535.9	249.4	1,153.6	780.8
Depreciation and amortization	176.5	99.8	382.6	295.2
Operating income (loss)	345.7	246.1	870.3	868.6
Equity in earnings of transmission affiliate	40	18	70.4	52.8
Interest expense	103.8	60.4	225.6	181.7
Transmission Affiliate
Financial information of reportable operating segments
Equity in earnings of transmission affiliate	40	18	70.4	52.8
Eliminations and Reconciling Items
Financial information of reportable operating segments
Operating revenues	(103.6)	(98.7)	(307.1)	(294.3)
Other operation and maintenance	(103.6)	(97.4)	(306.6)	(290.5)
Depreciation and amortization	0	(0.1)	(0.1)	0
Operating income (loss)	0	0	0	0
Equity in earnings of transmission affiliate	0.1	0	0.2	0
Interest expense	(2.4)	(0.2)	(2.4)	(0.5)
Regulated Operation
Financial information of reportable operating segments
Operating revenues	1,663.7	1,017.7	4,020.5	3,729.6
Other operation and maintenance	626	337.4	1,363.4	1,048.6
Depreciation and amortization	153.6	82.8	325.3	244.1
Operating income (loss)	256.4	158.4	673.3	606.3
Equity in earnings of transmission affiliate	40.2	18	70.6	52.8
Interest expense	58.8	32.1	122.9	96.8
Regulated Operation | Wisconsin
Financial information of reportable operating segments
Operating revenues	1,442.3	1,017.7	3,799.1	3,729.6
Other operation and maintenance	501.9	337.4	1,239.3	1,048.6
Depreciation and amortization	117.5	82.8	289.2	244.1
Operating income (loss)	256.6	158.4	673.5	606.3
Equity in earnings of transmission affiliate	0.2	0	0.2	0
Interest expense	46.5	32.1	110.6	96.8
Regulated Operation | Illinois
Financial information of reportable operating segments
Operating revenues	171.8	0	171.8	0
Other operation and maintenance	101	0	101	0
Depreciation and amortization	31.2	0	31.2	0
Operating income (loss)	3.5	0	3.5	0
Equity in earnings of transmission affiliate	0	0	0	0
Interest expense	9.7	0	9.7	0
Regulated Operation | Other States
Financial information of reportable operating segments
Operating revenues	49.6	0	49.6	0
Other operation and maintenance	23.1	0	23.1	0
Depreciation and amortization	4.9	0	4.9	0
Operating income (loss)	(3.7)	0	(3.7)	0
Equity in earnings of transmission affiliate	0	0	0	0
Interest expense	2.6	0	2.6	0
Regulated Operation | Transmission Affiliate
Financial information of reportable operating segments
Operating revenues	0	0	0	0
Other operation and maintenance	0	0	0	0
Depreciation and amortization	0	0	0	0
Operating income (loss)	0	0	0	0
Equity in earnings of transmission affiliate	40	18	70.4	52.8
Interest expense	0	0	0	0
Unregulated Operation | We Power LLC
Financial information of reportable operating segments
Operating revenues	110.7	109	333.1	328.1
Other operation and maintenance	0.6	0.4	3.7	3.6
Depreciation and amortization	16.9	16.7	50.6	49.9
Operating income (loss)	93.2	92	278.9	274.6
Equity in earnings of transmission affiliate	0	0	0	0
Interest expense	15.8	16.1	47.6	48.6
Unregulated Operation | Corporate and Other
Financial information of reportable operating segments
Operating revenues	27.9	5.3	31.3	8.6
Other operation and maintenance	12.9	9	93.1	19.1
Depreciation and amortization	6	0.4	6.8	1.2
Operating income (loss)	(3.9)	(4.3)	(81.9)	(12.3)
Equity in earnings of transmission affiliate	(0.3)	0	(0.4)	0
Interest expense	$ 31.6	$ 12.4	$ 57.5	$ 36.8

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)	Jun. 29, 2015	Dec. 31, 2014USD ($)
Variable interest entities
Equity method investment, ownership interest (as a percent)			60.00%
Equity investment in ATC	$ 999.4			$ 424.1
Purchased power agreement
Variable interest entities
Firm capacity from purchased power agreement (in megawatts) | MW	236
Minimum energy requirements over the remaining term of the purchased power agreement (in megawatts) | MW	0
Remaining term of the purchased power agreement (in years)	7 years
Residual guarantee associated with the purchased power agreement	$ 0
Required payments over the remaining term of the purchased power agreement	141.3
Total capacity and lease payments	$ 40.2	$ 39.8
ATC
Variable interest entities
Equity method investment, ownership interest (as a percent)	60.00%
Equity investment in ATC	$ 999.4
Accounts payable due to ATC	$ 28.1

Commitments and Contingencies -

Commitments and Contingencies - Unconditional Purchase Obligations (Details) $ in Millions	Sep. 30, 2015USD ($)
Minimum future commitments for purchase obligations
Purchase obligations	$ 12,586.8

Commitments and Contingencies75

Commitments and Contingencies - Environmental Matters (Details) - Manufactured Gas Plant Remediation [Member] - Natural Gas Utility - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Manufactured Gas Plant Remediation
Regulatory Asset Recovery of Remediation Expenditures	$ 676.2	$ 45.9
Accrual for Environmental Loss Contingencies	$ 611.3	$ 32.6

Supplemental Cash Flow Inform76

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Supplemental Cash Flow Information (Textuals)
Cash paid for interest, net of amount capitalized	$ 151	$ 143.4
Cash paid for income taxes, net of refunds	2	22
Accounts payable related to construction costs	179.1	4.9
Amortization of deferred revenue	30.3	$ 41.7
Restricted Cash and Cash Equivalents, Noncurrent	$ 108.7