WEC Energy (WEC) 10-K 27 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Jan. 31, 2014	Jun. 30, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'WISCONSIN ENERGY CORP	'	'
Entity Central Index Key	'0000783325	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Amendment Flag	'false	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$9.30
Entity Common Stock, Shares Outstanding (actual number of shares)	'	225,946,296	'

Consolidated_Income_Statements

Consolidated Income Statements (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Revenues	$4,519	$4,246.40	$4,486.40
Operating Expenses	'	'	'
Fuel and purchased power	1,153	1,098.60	1,169.70
Cost of gas sold	674.1	545.8	728.7
Other operation and maintenance	1,155	1,116.10	1,256.80
Depreciation and amortization	388.1	364.2	330.2
Property and revenue taxes	116.7	121.4	113.7
Total Operating Expenses	3,486.90	3,246.10	3,599.10
Revenue from Grants	48	0	0
Operating Income	1,080.10	1,000.30	887.3
Income (Loss) from Equity Method Investments	68.4	65.5	61.6
Other Income and Deductions, net	18.8	34.8	62.7
Interest Expense, net	252.1	248.2	235.8
Income (Loss) from Continuing Operations Before Income Taxes	915.3	852.6	776.7
Total Income Tax Expense, Amount	337.9	306.3	263.9
Income from Continuing Operations	577.4	546.3	512.8
Income from Discontinued Operations, Net of Tax	0	0	13.4
Net Income	577.4	546.3	526.2
Earnings Per Share (Basic)	'	'	'
Continuing Operations	$2.54	$2.37	$2.20
Discontinued Operations	$0	$0	$0.06
Total Earnings Per Share (Basic)	$2.54	$2.37	$2.26
Earnings Per Share (Diluted)	'	'	'
Continuing Operations	$2.51	$2.35	$2.18
Discontinued Operations	$0	$0	$0.06
Total Earnings Per Share (Diluted)	$2.51	$2.35	$2.24
Weighted Average Common Shares Outstanding (Millions)	'	'	'
Basic	227.6	230.2	232.6
Diluted	229.7	232.8	235.4
Transmission Affiliate [Member]	'	'	'
Operating Expenses	'	'	'
Income (Loss) from Equity Method Investments	$68.50	$65.70	$62.50

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Property, Plant and Equipment	'		'
In service	$14,966.30		$14,238.80
Accumulated depreciation	-4,257.10		-4,036
In service, net	10,709.20		10,202.80
Construction work in progress	149.6		315.9
Leased facilities, net	47.8		53.5
Net Property, Plant and Equipment	10,906.60		10,572.20
Investments	'		'
Equity investment in transmission affiliate	402.7		378.3
Other	36.1		35.5
Total Investments	438.8		413.8
Current Assets	'		'
Cash and cash equivalents	26		35.6
Accounts receivable, net of allowance for doubtful accounts of $61.0 and $58.0	406		285.3
Accrued revenues	321.1		278.1
Materials, supplies and inventories	329.4		360.7
Deferred Tax Assets, Net, Current	310		105.3
Prepayments	145.7		145.5
Other	12.9		62.1
Total Current Assets	1,551.10		1,272.60
Deferred Charges and Other Assets	'		'
Regulatory assets	1,108.50		1,380.30
Goodwill	441.9		441.9
Other	322.5		204.2
Total Deferred Charges and Other Assets	1,872.90		2,026.40
Total Assets	14,769.40	[1]	14,285	[1]
Capitalization	'		'
Common equity	4,233		4,135.10
Preferred Stock	30.4		30.4
Long-term debt	4,363.20		4,453.80
Total Capitalization	8,626.60		8,619.30
Current Liabilities	'		'
Long-term debt due currently	342.2		412.1
Short-term debt	537.4		394.6
Accounts payable	342.6		368.4
Accrued payroll and benefits	96.9		100.9
Other	177.3		165.4
Total Current Liabilities	1,496.40		1,441.40
Deferred Credits and Other Liabilities	'		'
Regulatory liabilities	879.1		868.4
Deferred income taxes - long-term	2,634		2,117
Deferred revenue, net	664.2		709.7
Pension and other benefit obligations	173.2		244
Other long-term liabilities	295.9		285.2
Total Deferred Credits and Other Liabilities	4,646.40		4,224.30
Commitments and Contingencies (Note Q)	'		'
Total Capitalization and Liabilities	$14,769.40		$14,285
[1]	An elimination of $2,231.2 million, $2,286.7 million and $2,369.0 million is included in Total Assets as of December 31, 2013, 2012 and 2011, respectively, for all PTF-related activity between We Power and Wisconsin Electric.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current Assets	'	'
Allowance on accounts receivable	$61	$58

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Activities	'	'	'
Net income	$577.40	$546.30	$526.20
Reconciliation to cash	'	'	'
Depreciation and amortization	400.2	371.7	336.4
Deferred income taxes and investment tax credits, net	312.7	293.2	430.6
Contributions to qualified benefit plans	0	-100	-277.4
Change in -	'	'	'
Accounts receivable and accrued revenues	-162.9	38.3	30.1
Inventories	31.3	21.3	-2.9
Other current assets	2.8	12.1	-20.5
Accounts payable	-14.8	43.8	11.8
Accrued income taxes, net	36.6	116.9	-87.4
Deferred costs, net	-8.7	9.2	25.9
Other current liabilities	7.2	-14.9	44.1
Other, net	49.2	-164	-23.5
Cash Provided by Operating Activities	1,231	1,173.90	993.4
Investing Activities	'	'	'
Capital expenditures	-687.4	-707	-830.8
Investment in transmission affiliate	-10.5	-15.7	-6.6
Proceeds from asset sales	2.5	8.7	41.5
Change in restricted cash	2.7	42.8	-37.2
Payments for (Proceeds from) Removal Costs	-37.8	-38.3	-16.9
Other, net	-15.3	-20.1	-42.5
Cash Used in Investing Activities	-745.8	-729.6	-892.5
Financing Activities	'	'	'
Exercise of stock options	48.5	49.8	54.4
Purchase of common stock	-223.4	-153.2	-193.9
Dividends paid on common stock	-328.9	-276.3	-242
Issuance of long-term debt	251	251.8	720
Retirement and repurchase of long-term debt	-397.2	-20.3	-466.6
Change in short-term debt	142.8	-275.3	12
Other, net	12.4	0.7	4.8
Cash Used in Financing Activities	-494.8	-422.8	-111.3
Change in Cash and Cash Equivalents	-9.6	21.5	-10.4
Cash and Cash Equivalents at Beginning of Year	35.6	14.1	24.5
Cash and Cash Equivalents at End of Year	$26	$35.60	$14.10

Consolidated_Statements_of_Com

Consolidated Statements of Common Equity (USD $)	Total	Common Stock [Member]	Other Paid In Capital [Member]	Retained Earnings [Member]
In Millions
Beginning - Balance at Dec. 31, 2010	$3,802.10	$2.30	$721.50	$3,078.30
Net income	526.2	'	'	526.2
Common stock cash dividends of $1.04, $1.20, and $1.445 per share for Year ended 2011, 2012 and 2013, respectively	-242	'	'	-242
Exercise of stock options	54.4	'	54.4	'
Purchase of common stock	-193.9	'	-193.9	'
Tax benefit from share based compensation	11.9	'	11.9	'
Stock-based compensation and other	4.6	'	4.6	'
Ending - Balance at Dec. 31, 2011	3,963.30	2.3	598.5	3,362.50
Net income	546.3	'	'	546.3
Common stock cash dividends of $1.04, $1.20, and $1.445 per share for Year ended 2011, 2012 and 2013, respectively	-276.3	'	'	-276.3
Exercise of stock options	49.8	'	49.8	'
Purchase of common stock	-153.2	'	-153.2	'
Stock-based compensation and other	5.2	'	5.2	'
Ending - Balance at Dec. 31, 2012	4,135.10	2.3	500.3	3,632.50
Net income	577.4	'	'	577.4
Common stock cash dividends of $1.04, $1.20, and $1.445 per share for Year ended 2011, 2012 and 2013, respectively	-328.9	'	'	-328.9
Exercise of stock options	48.5	'	48.5	'
Purchase of common stock	-223.4	'	-223.4	'
Tax benefit from share based compensation	18.1	'	18.1	'
Stock-based compensation and other	6.2	'	6.2	'
Ending - Balance at Dec. 31, 2013	$4,233	$2.30	$349.70	$3,881

Consolidated_Statements_of_Com1

Consolidated Statements of Common Equity (Parenthetical) (Retained Earnings [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Retained Earnings [Member]	'	'	'
Common stock cash dividends per share	$1.45	$1.20	$1.04

Consolidated_Statements_of_Cap

Consolidated Statements of Capitalization (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Common Equity	$4,233		$4,135.10
Preferred Stock	30.4		30.4
Obligations under capital leases	104.3		120
Unamortized discount, net and other	-25.6		-27
Long-term debt due currently	-342.2		-412.1
Total Long-Term Debt	4,363.20		4,453.80
Total Capitalization	8,626.60		8,619.30
Debentures (unsecured), 4.50% due 2013 [Member]	'		'
Long-Term debt, Unsecured	0		300
Debentures (unsecured), 6.60% due 2013 [Member]	'		'
Long-Term debt, Unsecured	0		45
Debentures (unsecured), 6.00% due 2014 [Member]	'		'
Long-Term debt, Unsecured	300		300
Debentures (unsecured), 5.20% due 2015 [Member]	'		'
Long-Term debt, Unsecured	125		125
Debentures (unsecured), 6.25% due 2015 [Member]	'		'
Long-Term debt, Unsecured	250		250
Debentures (unsecured), 1.70% due 2018 [Member]	'		'
Long-Term debt, Unsecured	250		0
Debentures (unsecured), 4.25% due 2019 [Member]	'		'
Long-Term debt, Unsecured	250		250
Debentures (unsecured) 2.95% due 2021 [Member]	'		'
Long-Term debt, Unsecured	300		300
Debentures (unsecured), 6-1/2% due 2028 [Member]	'		'
Long-Term debt, Unsecured	150		150
Debentures (unsecured), 5.625% due 2033 [Member]	'		'
Long-Term debt, Unsecured	335		335
Debentures (unsecured), 5.90% due 2035 [Member]	'		'
Long-Term debt, Unsecured	90		90
Notes (secured, nonrecourse), 4.91% due 2013-2030 [Member] [Member]	'		'
Long-Term debt, Secured	122.1	[1]	126.7	[1]
Debentures (unsecured), 5.70% due 2036 [Member]	'		'
Long-Term debt, Unsecured	300		300
Debentures (unsecured), 3.65% due 2042 [Member]	'		'
Long-Term debt, Unsecured	250		250
Debentures (unsecured), 6-7/8% due 2095 [Member]	'		'
Long-Term debt, Unsecured	100		100
Notes (secured, nonrecourse), 4.81% effective rate due 2030 [Member]	'		'
Long-Term debt, Secured	2		2
Notes (secured, nonrecourse), 5.209% due 2013-2030 [Member] [Member]	'		'
Long-Term debt, Secured	231.5	[2]	238.6	[2]
Notes (secured, nonrecourse), 4.673% due 2013-2031 [Member] [Member]	'		'
Long-Term debt, Secured	190.9	[2]	196.7	[2]
Notes (secured, nonrecourse), 6.00% due 2013-2033 [Member] [Member]	'		'
Long-Term debt, Secured	138.4	[1]	142.1	[1]
Notes (secured, nonrecourse), 6.09% due 2030-2040 [Member]	'		'
Long-Term debt, Secured	275	[2]	275	[2]
Notes (secured, nonrecourse), 5.848% due 2031-2041 [Member]	'		'
Long-Term debt, Secured	215	[2]	215	[2]
Notes (secured, nonrecourse) 6.00% due 2021 [Member]	'		'
Long-Term debt, Secured	1.8		1.8
Notes (unsecured), 6.51% due 2013 [Member]	'		'
Long-Term debt, Unsecured	0		30
Notes (unsecured), 6.94% due 2028 [Member]	'		'
Long-Term debt, Unsecured	50		50
Notes (unsecured), 0.504% variable rate due 2016 [Member]	'		'
Long-Term debt, Unsecured	67	[3]	67	[3]
Notes (unsecured), 0.504% variable rate due 2030 [Member]	'		'
Long-Term debt, Unsecured	80	[3]	80	[3]
Notes (unsecured), 6.20% due 2033 [Member]	'		'
Long-Term debt, Unsecured	200		200
Junior Notes (unsecured), 6.25% due 2067 [Member]	'		'
Long-Term debt, Unsecured	500		500
Wisconsin Energy Corporation [Member]	'		'
Preferred Stock	0		0
Wisconsin Electric [Member]	'		'
Preferred Stock	30.4		30.4
Long-Term debt, Unsecured	147		147
Six Per Cent. Preferred Stock [Member]	'		'
Preferred Stock	4.4		'
Six Per Cent. Preferred Stock [Member] | Wisconsin Electric [Member]	'		'
Preferred Stock	'		4.4
Serial preferred stock, 3.60% Series Redeemable [Member]	'		'
Preferred Stock	26		'
Serial preferred stock, 3.60% Series Redeemable [Member] | Wisconsin Electric [Member]	'		'
Preferred Stock	'		26
Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding [Member]	'		'
Preferred Stock	0		'
Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding [Member] | Wisconsin Electric [Member]	'		'
Preferred Stock	'		$0
[1]	(b) Senior notes are secured by a collateral assignment of the leases between PWGS and Wisconsin Electric related to PWGS 1 and 2.
[2]	(c) Senior notes are secured by a collateral assignment of the leases between ERGSS and Wisconsin Electric related to OC 1 and 2.
[3]	Variable interest rate as of December 31, 2013.

Consolidated_Statements_of_Cap1

Consolidated Statements of Capitalization (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Debentures (unsecured), 4.50% due 2013 [Member]	'	'
Debt instrument stated interest rate (percentage)	4.50%	4.50%
Debentures (unsecured), 6.60% due 2013 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.60%	6.60%
Debentures (unsecured), 6.00% due 2014 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.00%	6.00%
Debentures (unsecured), 5.20% due 2015 [Member]	'	'
Debt instrument stated interest rate (percentage)	5.20%	5.20%
Debentures (unsecured), 6.25% due 2015 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.25%	6.25%
Debentures (unsecured), 1.70% due 2018 [Member]	'	'
Debt instrument stated interest rate (percentage)	1.70%	1.70%
Debentures (unsecured), 4.25% due 2019 [Member]	'	'
Debt instrument stated interest rate (percentage)	4.25%	4.25%
Debentures (unsecured) 2.95% due 2021 [Member]	'	'
Debt instrument stated interest rate (percentage)	2.95%	2.95%
Debentures (unsecured), 6-1/2% due 2028 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.50%	6.50%
Debentures (unsecured), 5.625% due 2033 [Member]	'	'
Debt instrument stated interest rate (percentage)	5.63%	5.63%
Debentures (unsecured), 5.90% due 2035 [Member]	'	'
Debt instrument stated interest rate (percentage)	5.90%	5.90%
Debentures (unsecured), 5.70% due 2036 [Member]	'	'
Debt instrument stated interest rate (percentage)	5.70%	5.70%
Debentures (unsecured), 3.65% due 2042 [Member]	'	'
Debt instrument stated interest rate (percentage)	3.65%	3.65%
Debentures (unsecured), 6-7/8% due 2095 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.88%	6.88%
Notes (secured, nonrecourse), 4.81% effective rate due 2030 [Member]	'	'
Debt instrument stated interest rate (percentage)	4.81%	4.81%
Notes (secured, nonrecourse), 4.91% due 2013-2030 [Member] [Member]	'	'
Debt instrument stated interest rate (percentage)	4.91%	4.91%
Notes (secured, nonrecourse), 5.209% due 2013-2030 [Member] [Member]	'	'
Debt instrument stated interest rate (percentage)	5.21%	5.21%
Notes (secured, nonrecourse), 4.673% due 2013-2031 [Member] [Member]	'	'
Debt instrument stated interest rate (percentage)	4.67%	4.67%
Notes (secured, nonrecourse), 6.00% due 2013-2033 [Member] [Member]	'	'
Debt instrument stated interest rate (percentage)	6.00%	6.00%
Notes (secured, nonrecourse), 6.09% due 2030-2040 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.09%	6.09%
Notes (secured, nonrecourse), 5.848% due 2031-2041 [Member]	'	'
Debt instrument stated interest rate (percentage)	5.85%	5.85%
Notes (secured, nonrecourse) 6.00% due 2021 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.00%	6.00%
Notes (unsecured), 6.51% due 2013 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.51%	6.51%
Notes (unsecured), 6.94% due 2028 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.94%	6.94%
Notes (unsecured), 0.504% variable rate due 2016 [Member]	'	'
Long-term debt, percentage bearing variable interest rate	0.50%	0.50%
Notes (unsecured), 0.504% variable rate due 2030 [Member]	'	'
Long-term debt, percentage bearing variable interest rate	0.50%	0.50%
Notes (unsecured), 6.20% due 2033 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.20%	6.20%
Junior Notes (unsecured), 6.25% due 2067 [Member]	'	'
Debt instrument stated interest rate (percentage)	6.25%	6.25%
Wisconsin Energy Corporation [Member]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	15,000,000	15,000,000
Preferred stock, shares outstanding	0	0
Six Per Cent. Preferred Stock [Member]	'	'
Preferred stock, shares authorized	45,000	'
Preferred stock, shares outstanding	44,498	'
Six Per Cent. Preferred Stock [Member] | Wisconsin Electric [Member]	'	'
Preferred stock, par value	$100	$100
Preferred stock, shares authorized	'	45,000
Preferred stock, shares outstanding	'	44,498
Preferred stock dividend rate, percentage	6.00%	6.00%
Serial preferred stock, 3.60% Series Redeemable [Member]	'	'
Preferred stock, shares outstanding	260,000	'
Serial preferred stock, 3.60% Series Redeemable [Member] | Wisconsin Electric [Member]	'	'
Preferred stock, par value	$100	$100
Preferred stock, shares outstanding	'	260,000
Preferred stock dividend rate, percentage	3.60%	3.60%

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Summary of Significant Accounting Policies [Abstract]	'
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	General:   Our consolidated financial statements include the accounts of Wisconsin Energy Corporation (Wisconsin Energy, the Company, our, we or us), a diversified holding company, as well as our subsidiaries in the following reportable segments:
	•	Utility Energy Segment -- Consisting of Wisconsin Electric and Wisconsin Gas, engaged primarily in the generation of electricity and the distribution of electricity and natural gas; and
	•	Non-Utility Energy Segment -- Consisting primarily of We Power, engaged principally in the ownership of electric power generating facilities for long-term lease to Wisconsin Electric.
	Our Corporate and Other segment includes Wispark, which develops and invests in real estate. We have also eliminated all intercompany transactions from the consolidated financial statements.
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and disclosure of contingent assets and liabilities at the date of financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Reclassifications and Adjustments:  As of December 31, 2013, we have presented the tax effect of net operating loss carryforwards within current deferred tax assets, net on the consolidated balance sheets. As of December 31, 2012, $59.0 million representing the tax effect of net operating loss carryforwards were included in income taxes receivable, which is a line item that has now been condensed within other current assets on the consolidated balance sheets. This $59.0 million amount has been adjusted in the consolidated balance sheets as of December 31, 2012 to conform to the December 31, 2013 presentation, and conforming changes have been made in the consolidated statements of cash flows and in the notes to the consolidated financial statements. For additional information related to our deferred tax assets, see Note G.
	In addition, we have adjusted the presentation of regulatory assets and liabilities to present amounts as noncurrent assets and liabilities on the consolidated balance sheets. Prior period amounts recorded within other current assets and liabilities have been reclassified to conform to the current presentation. For additional information related to regulatory assets and liabilities, see Note C.
	Revenues:   We recognize energy revenues on the accrual basis and include estimated amounts for services rendered but not billed.
	Our retail electric rates in Wisconsin are established by the PSCW and include base amounts for fuel and purchased power costs. The electric fuel rules in Wisconsin allow us to defer, for subsequent rate recovery or refund, any under-collection or over-collection of fuel costs that are outside of the symmetrical fuel cost tolerance, which the PSCW set at plus or minus 2% of the approved fuel cost plan. The deferred under-collected amounts are subject to an excess revenues test.
	Our retail gas rates include monthly adjustments which permit the recovery or refund of actual purchased gas costs. We defer any difference between actual gas costs incurred (adjusted for a sharing mechanism) and costs recovered through rates as a current asset or liability. The deferred balance is returned to or recovered from customers at intervals throughout the year.
	We recognize We Power revenues (consisting of the lease payments included in rates and the amortization of the deferred revenue) on a levelized basis over the term of the lease.
	Accounting for MISO Energy Transactions:   The MISO Energy Markets operate under both day-ahead and real-time markets. We record energy transactions in the MISO Energy Markets on a net basis for each hour.
	Other Income and Deductions, Net:   We recorded the following items in Other Income and Deductions, net for the years ended December 31:
	Other Income and Deductions, net		2013			2012				2011
			(Millions of Dollars)
	AFUDC - Equity		$	18.3		$	35.3			$	59.4
	Other, net		0.5			(0.5		)		3.3
	Total Other Income and Deductions, net		$	18.8		$	34.8			$	62.7
	Property and Depreciation:   We record property, plant and equipment at cost. Cost includes material, labor, overheads and capitalized interest. Utility property also includes AFUDC - Equity. Additions to and significant replacements of property are charged to property, plant and equipment at cost; minor items are charged to maintenance expense. The cost of depreciable utility property less salvage value is charged to accumulated depreciation when property is retired.
	We recorded the following property in service by segment as of December 31:
	Property In Service		2013			2012
			(Millions of Dollars)
	Utility Energy		$	11,779.80		$	11,080.90
	Non-Utility Energy		3,091.30			3,068.50
	Other		95.2			89.4
	Total		$	14,966.30		$	14,238.80
	Our utility depreciation rates are certified by the PSCW and MPSC and include estimates for salvage value and removal costs. Depreciation as a percent of average depreciable utility plant was 2.9% in 2013 and 2012, and 2.8% in 2011.
	We depreciate our We Power assets over the estimated useful life of the various property components. The components have useful lives of between 10 to 45 years for PWGS 1 and PWGS 2, and 10 to 55 years for OC 1 and OC 2.
	Our regulated utilities collect in their rates amounts representing future removal costs for many assets that do not have an associated Asset Retirement Obligation (ARO). We record a regulatory liability on our balance sheet for the estimated amounts we have collected in rates for future removal costs less amounts we have spent in removal activities. This regulatory liability was $724.5 million as of December 31, 2013 and $725.0 million as of December 31, 2012.
	We recorded the following Construction Work in Progress (CWIP) by segment as of December 31:
	CWIP		2013			2012
			(Millions of Dollars)
	Utility Energy		$	132.7		$	298.2
	Non-Utility Energy		16.5			13.3
	Other		0.4			4.4
	Total		$	149.6		$	315.9
	Allowance For Funds Used During Construction - Regulated:   AFUDC is included in utility plant accounts and represents the cost of borrowed funds (AFUDC - Debt) used during plant construction, and a return on stockholders' capital (AFUDC - Equity) used for construction purposes. AFUDC - Debt is recorded as a reduction of interest expense, and AFUDC - Equity is recorded in Other Income and Deductions, net.
	Our regulated utility segment recorded the following AFUDC for the years ended December 31:
		2013			2012				2011
		(Millions of Dollars)
	AFUDC - Debt	$	7.7		$	14.7			$	24.7
	AFUDC - Equity	$	18.3		$	35.3			$	59.4
	Capitalized Interest and Carrying Costs - Non-Regulated Energy:   As part of the construction of the PTF electric generating units, we capitalized interest during construction. As allowed under the lease agreements, we were able to collect the carrying costs during the construction of the PTF generating units from our utility customers. The carrying costs that we collected during construction have been recorded as deferred revenue on our balance sheet and we are amortizing the deferred carrying costs to revenue over the individual lease terms.
	Earnings per Common Share:   We compute basic earnings per common share by dividing our net income attributed to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per common share is computed by dividing net income attributed to common shareholders by the weighted average number of common shares outstanding during the period, adjusted for the exercise and/or conversion of all potentially dilutive securities. Such dilutive securities include in-the-money stock options. All stock options outstanding during 2013, 2012 and 2011 were included in the computation of diluted earnings per share. Anti-dilutive shares are excluded from the calculation.
	Materials, Supplies and Inventories:   Our inventory as of December 31 consists of:
	Materials, Supplies and Inventories		2013			2012
			(Millions of Dollars)
	Fossil Fuel		$	117.7		$	165.5
	Materials and Supplies		133.9			121.9
	Natural Gas in Storage		77.8			73.3
	Total		$	329.4		$	360.7
	Substantially all fossil fuel, materials and supplies, and natural gas in storage inventories are recorded using the weighted-average cost method of accounting.
	Regulatory Accounting:   The economic effects of regulation can result in regulated companies recording costs that have been or are expected to be allowed in the rate-making process in a period different from the period in which the costs would be charged to expense by an unregulated enterprise. When this occurs, costs are deferred as regulatory assets on the balance sheet and expensed in the periods when they are reflected in rates. We defer regulatory assets pursuant to specific or generic orders issued by our regulators. Additionally, regulators can impose regulatory liabilities upon a regulated company for amounts previously collected from customers and for amounts that are expected to be refunded to customers. In general, regulatory assets are recovered in a period between one to eight years. For further information, see Note C.
	Asset Retirement Obligations:   We record a liability for a legal ARO in the period in which it is incurred. When a new legal obligation is recorded, we capitalize the costs of the liability by increasing the carrying amount of the related long-lived asset. We accrete the liability to its present value each period and depreciate the capitalized cost over the useful life of the related asset. At the end of the asset's useful life, we settle the obligation for its recorded amount or incur a gain or loss. As it relates to our regulated operations, we apply regulatory accounting guidance and recognize regulatory assets or liabilities for the timing differences between when we recover legal AROs in rates and when we would recognize these costs. For further information, see Note E.
	Derivative Financial Instruments:   We have derivative physical and financial instruments which we report at fair value. For further information, see Note L.
	Cash and Cash Equivalents:   Cash and cash equivalents include marketable debt securities acquired three months or less from maturity.
	Margin Accounts:   Cash deposited in brokerage accounts for margin requirements is recorded in Other Current Assets on our Consolidated Balance Sheets.
	Goodwill:   Goodwill reflects the cost of an acquisition in excess of the fair values assigned to identifiable net assets acquired. As of December 31, 2013 and 2012, we had $441.9 million of goodwill recorded at the utility energy segment, which related to our acquisition of Wisconsin Gas in 2000.
	Goodwill is not subject to amortization. However, it is subject to fair value-based rules for measuring impairment, and resulting write-downs, if any, are to be reflected in operating expense. Fair value is assessed by considering future discounted cash flows, a comparison of fair value based on public company trading multiples, and merger and acquisition transaction multiples for similar companies. This evaluation utilizes the information available under the circumstances, including reasonable and supportable assumptions and projections. We perform our annual impairment test as of August 31. There was no impairment to the recorded goodwill balance as of our annual 2013 impairment test date.
	Impairment or Disposal of Long Lived Assets:   We carry property, equipment and goodwill related to businesses held for sale at the lower of cost or estimated fair value less cost to sell. As of December 31, 2013, we had no assets classified as Held for Sale. Long-lived assets are tested for recoverability whenever events or changes in circumstances indicate that their carrying value may not be recoverable from the use and eventual disposition of the asset based on the remaining useful life. An impairment loss is recognized when the carrying amount of an asset is not recoverable and exceeds the fair value of the asset. The carrying amount of an asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. An impairment loss is measured as the excess of the carrying amount of the asset in comparison to the fair value of the asset.
	Investments:   We account for investments in other affiliated companies in which we do not maintain control using the equity method of accounting. We had a total ownership interest of approximately 26.2% in ATC as of December 31, 2013 and 2012. We are represented by one out of ten ATC board members, each of whom has one vote. Due to the voting requirements, no individual member has more than 10% of the voting control. For further information regarding such investments, see Note P.
	Income Taxes:   We follow the liability method in accounting for income taxes. Accounting guidance for income taxes requires the recording of deferred assets and liabilities to recognize the expected future tax consequences of events that have been reflected in our financial statements or tax returns and the adjustment of deferred tax balances to reflect tax rate changes. We are required to assess the likelihood that our deferred tax assets would expire before being realized. If we conclude that certain deferred tax assets are likely to expire before being realized, a valuation allowance would be established against those assets. GAAP requires that, if we conclude in a future period that it is more likely than not that some or all of the deferred tax assets would be realized before expiration, we reverse the related valuation allowance in that period. Any change to the allowance, as a result of a change in judgment about the realization of deferred tax assets, is reported in income tax expense.
Investment tax credits associated with regulated operations are deferred and amortized over the life of the assets. We file a consolidated Federal income tax return. Accordingly, we allocate Federal current tax expense benefits and credits to our subsidiaries based on their separate tax computations. For further information, see Note G.
We recognize interest and penalties accrued related to unrecognized tax benefits in Income Taxes in our Consolidated Income Statements, as well as Regulatory Assets or Regulatory Liabilities in our Consolidated Balance Sheets.
We collect sales and use taxes from our customers and remit these taxes to governmental authorities. These taxes are recorded in our Consolidated Income Statements on a net basis.
Stock Options:   We estimate the fair value of stock options using the binomial pricing model. We report unearned stock-based compensation associated with non-vested restricted stock and performance share awards activity within Other Paid in Capital in our Consolidated Statements of Common Equity. We report excess tax benefits as a financing cash inflow. Historically, all stock options have been granted with an exercise price equal to the fair market value of the common stock on the date of grant and expire no later than 10 years from grant date. For a discussion of the impacts to our Consolidated Financial Statements, see Note H.
The fair value of our stock options was calculated using a binomial option-pricing model using the following weighted-average assumptions:
	2013		2012	2011
Risk-free interest rate	0.1% - 1.9%		0.1% - 2.0%	0.2% - 3.4%
Dividend yield	3.70%		3.90%	3.90%
Expected volatility	18.00%		19.00%	19.00%
Expected life (years)	5.9		5.9	5.5
Expected forfeiture rate	2.00%		2.00%	2.00%
Weighted-average fair value
of our stock options granted	$3.45		$3.34	$3.17
Treasury Grant:   In December 2013, we filed an application with the United States Treasury for a Section 1603 renewable energy grant related to the construction of our biomass facility in Rothschild, Wisconsin. The PSCW anticipated the recognition of this grant as income when it set rates for the two years beginning January 1, 2013. We provided bill credits to our customers in 2013, and this will continue into 2014. As of December 31, 2013, $48.0 million was recognized as income, which reflects the amount that was returned to customers in the form of bill credits during the year. We recorded an $82.6 million receivable, and deferred the balance that we expect to benefit our customers in the future. The accounting reflects the regulatory treatment of the grant.
The PSCW approved escrow accounting treatment for the Treasury Grant. Under escrow accounting, we true-up any differences between the actual grant proceeds received and the grant proceeds passed on to customers in the form of bill credits.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
RECENT ACCOUNTING PRONOUNCEMENTS	'
	RECENT ACCOUNTING PRONOUNCEMENTS
	Offsetting Assets and Liabilities: In January 2013, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2013-01, Disclosures about Offsetting Assets and Liabilities. The guidance requires enhanced disclosures about derivatives. Both gross and net information related to eligible transactions is required under the guidance. This guidance is effective for fiscal years and interim periods beginning on or after January 1, 2013, and must be applied retrospectively. We adopted this guidance on January 1, 2013, and applied it retrospectively. The adoption and retrospective application of this guidance did not have any material impact on our financial statements. See Note L -- Derivative Instruments for the enhanced disclosures.

Regulatory_Assets_and_Liabilit

Regulatory Assets and Liabilities	12 Months Ended
	Dec. 31, 2013
Regulatory Assets and Liabilities Disclosure [Abstract]	'
REGULATORY ASSETS AND LIABILITIES	'
	REGULATORY ASSETS AND LIABILITIES
	Our primary regulator, the PSCW, considers our regulatory assets and liabilities in two categories, escrowed and deferred. In escrow accounting we expense amounts that are included in rates. If actual costs exceed or are less than the amounts that are allowed in rates, the difference in cost is escrowed on the balance sheet as a regulatory asset or regulatory liability and the escrowed balance is considered in setting future rates. Under deferred cost accounting, we defer amounts to our balance sheet based upon orders or correspondence with our regulators. These deferred costs will be considered in future rate setting proceedings. As of December 31, 2013, we had $10.1 million of regulatory assets not earning a return and $82.7 million of regulatory assets earning a return based on short-term interest rates.
	In December 2012, the PSCW issued a rate order effective January 1, 2013 that, among other things, reaffirmed our accounting for the regulatory assets and liabilities identified below.
	Our regulatory assets and liabilities as of December 31 consist of:
		2013		2012
		(Millions of Dollars)
	Regulatory Assets
	Deferred unrecognized pension costs	$	537.6	$	731.5
	Deferred income tax related	169.5		176.5
	Escrowed electric transmission costs	126.8		114.1
	Escrowed conservation	66.9		73.5
	Deferred plant related -- capital lease	56.5		66.6
	Deferred environmental costs	47		47.4
	Other, net	104.2		170.7
	Total regulatory assets	$	1,108.50	$	1,380.30
	Regulatory Liabilities
	Deferred cost of removal obligations	$	724.5	$	725
	Escrowed bad debt costs	64.6		81.1
	Other, net	90		62.2
	Total regulatory liabilities	$	879.1	$	868.3

Asset_Sales_Divestitures_and_D

Asset Sales, Divestitures and Discontinued Operations	12 Months Ended
	Dec. 31, 2013
Asset Sales Divestitures and Discontinued Operations [Abstract]	'
ASSET SALES, DIVESTITURES AND DISCONTINUED OPERATIONS	'
	ASSET SALES, DIVESTITURES AND DISCONTINUED OPERATIONS
	The following table summarizes the net impacts of the discontinued operations on our earnings for the years ended December 31:
		2013		2012		2011
		(Millions of Dollars)
	Income from Continuing Operations	$	577.4	$	546.3	$	512.8
	Income from Discontinued other operations, net of tax (a)	—		—		13.4
	Net Income	$	577.4	$	546.3	$	526.2
	(a)	Primarily relates to the favorable resolution of uncertain state and federal tax positions associated with our previously discontinued manufacturing business.
	Edgewater Generating Unit 5:   On March 1, 2011, we sold our 25% interest in Edgewater Generating Unit 5 to WPL for our net book value, including working capital, of approximately $38 million. This transaction was treated as a sale of an asset.

Asset_Retirement_Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2013
Asset Retirement Obligation [Abstract]	'
ASSET RETIREMENT OBLIGATIONS	'
	ASSET RETIREMENT OBLIGATIONS
	AROs have been recorded for asbestos abatement at certain generation and substation facilities, and for obligations associated with the removal and dismantlement of generation facilities. AROs are recorded in other long-term liabilities on the Consolidated Balance Sheets. The following table presents the change in our AROs during 2013 and 2012:
		2013			2012
		(Millions of Dollars)
	Balance as of January 1	$	44.3		$	55.5
	Liabilities Settled	(4.4		)	(14.0		)
	Accretion	2.4			2.8
	Balance as of December 31	$	42.3		$	44.3

Variable_Interest_Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2013
Variable Interest Entities [Abstract]	'
VARIABLE INTEREST ENTITIES	'
	VARIABLE INTEREST ENTITIES
	The primary beneficiary of a variable interest entity must consolidate the related assets and liabilities. Certain disclosures are required by sponsors, significant interest holders in variable interest entities and potential variable interest entities.
	We assess our relationships with potential variable interest entities such as our coal suppliers, natural gas suppliers, coal and gas transporters, and other counterparties in power purchase agreements and joint ventures. In making this assessment, we consider the potential that our contracts or other arrangements provide subordinated financial support, the potential for us to absorb losses or rights to residual returns of the entity, the ability to directly or indirectly make decisions about the entities' activities and other factors.
	We have identified a purchased power agreement which represents a variable interest. This agreement is for 236 MW of firm capacity from a 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 nine 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 $215.9 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 contracts considered variable interests in 2013, 2012 and 2011 were $50.3 million, $45.8 million and $65.9 million, respectively. Our maximum exposure to loss is limited to the capacity payments under the contract.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
INCOME TAXES	'
	INCOME TAXES
	The following table is a summary of income tax expense for each of the years ended December 31:
	Income Taxes		2013				2012				2011
			(Millions of Dollars)
	Current tax expense (benefit)		$	25.2			$	13.1			$	(166.7	)
	Deferred income taxes, net		313.8				294.4				434.8
	Investment tax credit, net		(1.1		)		(1.2		)		(4.2		)
	Total Income Tax Expense		$	337.9			$	306.3			$	263.9
	The provision for income taxes for each of the years ended December 31 differs from the amount of income tax determined by applying the applicable U.S. statutory federal income tax rate to income before income taxes as a result of the following:
			2013							2012						2011
							Effective							Effective					Effective
	Income Tax Expense		Amount				Tax Rate			Amount				Tax Rate		Amount			Tax Rate
			(Millions of Dollars)
	Expected tax at statutory federal tax rates		$	320.3			35	%		$	298.4			35	%	$	271.8		35	%
	State income taxes net of federal tax benefit		49				5.3	%		43.3				5.1	%	40.1			5.2	%
	Production tax credits		(16.7		)		(1.8	)%		(15.9		)		(1.9	)%	(8.7		)	(1.1	)%
	Treasury Grant		(7.4		)		(0.8	)%		—				—	%	—			—	%
	AFUDC - Equity		(6.4		)		(0.7	)%		(12.3		)		(1.4	)%	(20.8		)	(2.7	)%
	Investment tax credit restored		(1.1		)		(0.1	)%		(1.2		)		(0.1	)%	(4.2		)	(0.5	)%
	Domestic production activities deduction		—				—	%		(12.6		)		(1.5	)%	(12.6		)	(1.6	)%
	Other, net		0.2				—	%		6.6				0.7	%	(1.7		)	(0.3	)%
	Total Income Tax Expense		$	337.9			36.9	%		$	306.3			35.9	%	$	263.9		34	%
	The components of deferred income taxes classified as net current assets and net long-term liabilities as of December 31 are as follows:
	Deferred Tax Assets		2013				2012
			(Millions of Dollars)
	Current
	Future federal tax benefits		$	309.7			$	59
	Employee benefits and compensation		13.8				14.9
	Other		56				81.1
	Total Current Deferred Tax Assets		379.5				155
	Non-current
	Deferred revenues		237				250
	Employee benefits and compensation		95.6				97
	Future federal tax benefits		32.5				334.7
	Property-related		28.2				28.3
	Construction advances		18.3				22.2
	Other		62.9				16.3
	Total Non-Current Deferred Tax Assets		474.5				748.5
	Total Deferred Tax Assets		$	854			$	903.5
	Deferred Tax Liabilities		2013				2012
			(Millions of Dollars)
	Current
	Prepaid items		$	69.5			$	49.7
	Total Current Deferred Tax Liabilities		69.5				49.7
	Non-current
	Property-related		2,574.40				2,339.40
	Employee benefits and compensation		238.5				244.3
	Investment in transmission affiliate		169.9				144.9
	Deferred transmission costs		50.8				45.7
	Other		74.9				91.2
	Total Non-current Deferred Tax Liabilities		3,108.50				2,865.50
	Total Deferred Tax Liabilities		$	3,178.00			$	2,915.20
	Consolidated Balance Sheet Presentation		2013				2012
	Current Deferred Tax Asset		$	310			$	105.3
	Non-Current Deferred Tax Liability		$	2,634.00			$	2,117.00
	Consistent with rate-making treatment, deferred taxes are offset in the above table for temporary differences which have related regulatory assets or liabilities.
	As of December 31, 2013, we had approximately $810.3 million and $58.6 million of net operating loss and tax credit carryforwards resulting in deferred tax assets of $283.6 million and $58.6 million, respectively. As of December 31, 2012, we had approximately $1,007.1 million and $41.2 million of net operating loss and tax credit carryforwards resulting in deferred tax assets of $352.5 million and $41.2 million, respectively. The tax credit and net operating loss carryforwards begin to expire in 2029. We anticipate that we will have future taxable income sufficient to utilize these deferred tax assets.
	We previously adopted accounting guidance related to uncertainty in income taxes. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
		2013				2012
		(Millions of Dollars)
	Balance as of January 1	$	11.3			$	11.1
	Additions for tax positions of prior years	—				10.8
	Reductions for tax positions of prior years	(2.9		)		(10.6		)
Balance as of December 31	$	8.4			$	11.3
The amount of unrecognized tax benefits as of December 31, 2013 and 2012 excludes deferred tax assets related to uncertainty in income taxes of $8.4 million and $10.2 million, respectively. As of December 31, 2013, there were no unrecognized tax benefits that, if recognized, would impact the effective tax rate for continuing operations. As of December 31, 2012, the net amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate for continuing operations was approximately $1.0 million.
We recognize interest and penalties accrued related to unrecognized tax benefits as a component of income tax expense. For the years ended December 31, 2013, 2012 and 2011, we recognized approximately $0.2 million, $0.2 million and $0.7 million, respectively, of accrued interest in the Consolidated Income Statements. For the years ended December 31, 2013 and 2012, we recognized no penalties in the Consolidated Income Statements. For the year ended 2011, we recognized a benefit of $0.3 million in the Consolidated Income Statements related to a reduction of accrued penalties. We had approximately $0.4 million and $0.3 million of interest accrued and no penalties accrued on the Consolidated Balance Sheets as of December 31, 2013 and 2012, respectively.
We do not anticipate any significant increases or decreases in the total amounts of unrecognized tax benefits within the next 12 months.
Our primary tax jurisdictions include the United States and the state of Wisconsin. Currently, the tax years of 2011 through 2013 are subject to Federal examination, and the tax years 2009 through 2013 are subject to examination by the state of Wisconsin.

Common_Equity

Common Equity	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
COMMON EQUITY	'
	COMMON EQUITY
	As of December 31, 2013 and 2012, we had 325,000,000 shares of common stock authorized under our charter, of which 225,962,959 and 229,039,456 common shares, respectively, were outstanding. All share-based compensation is currently fulfilled by purchases on the open market by our independent agents and do not dilute shareholders' ownership.
	Share-Based Compensation Plans:   We have a plan that was approved by stockholders that enables us to provide a long-term incentive through equity interests in Wisconsin Energy to outside directors, selected officers and key employees of the Company. The plan provides for the granting of stock options, stock appreciation rights, restricted stock awards and performance shares. Awards may be paid in common stock, cash or a combination thereof. We utilize the straight-line attribution method for recognizing share-based compensation expense. Accordingly, for employee awards, equity classified share-based compensation cost is measured at the grant date based on the fair value of the award, and is recognized as expense over the requisite service period. There were no modifications to the terms of outstanding stock options during the period.
	The following table summarizes recorded pre-tax share-based compensation expense and the related tax benefit for share-based awards made to our employees and directors as of December 31:
		2013				2012			2011
		(Millions of Dollars)
	Performance units	$	12.7			$	16.3		$	24.1
	Stock options	3.9				2.7			2.6
	Restricted stock	2.4				3			1.8
	Share-based compensation expense	$	19			$	22		$	28.5
	Related Tax Benefit	$	7.6			$	8.8		$	11.4
	Stock Options:   The exercise price of a stock option under the plan is to be no less than 100% of the common stock's fair market value on the grant date and options may not be exercised within six months of the grant date except in the event of a change in control. Option grants consist of non-qualified stock options that vest on a cliff-basis after a three year period. Options expire no later than 10 years from the date of grant. For further information regarding stock-based compensation and the valuation of our stock options, see Note A.
	We expect that substantially all of the outstanding options as of December 31, 2013 will be exercised.
	The following is a summary of our stock option activity during 2013:
	Stock Options		Number of Options			Weighted-Average Exercise Price			Weighted-Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (Millions)
	Outstanding as of January 1, 2013		8,919,669			$	23.86
	Granted		1,418,560			$	37.46
	Exercised		(2,238,489	)		$	21.67
	Forfeited		(10,030	)		$	35.37
	Outstanding as of December 31, 2013		8,089,710			$	26.84		5.4		$	117.3
	Exercisable as of December 31, 2013		5,708,920			$	23.16		4.1		$	103.8
	In January 2014, the Compensation Committee of the Board of Directors (Compensation Committee) awarded 899,500 non-qualified stock options with an exercise price of $41.03 to our officers and other key employees under its normal schedule of awarding long-term incentive compensation.
	The intrinsic value of options exercised during the years ended December 31, 2013, 2012 and 2011 was $44.5 million, $47.5 million and $36.1 million, respectively. Cash received from options exercised during the years ended December 31, 2013, 2012 and 2011 was $48.5 million, $49.8 million and $54.4 million, respectively. The actual tax benefit realized for the tax deductions from option exercises for the same periods was approximately $17.8 million, zero and $14.3 million, respectively.
	The following table summarizes information about stock options outstanding as of December 31, 2013:
			Options Outstanding								Options Exercisable
						Weighted-Average							Weighted-Average
	Range of Exercise Prices		Number of Options			Exercise Price			Remaining Contractual Life (Years)		Number of Options		Exercise Price		Remaining Contractual Life (Years)
	$16.72  to  $21.11		2,128,370			$	20.34		3.9		2,128,370		$	20.34	3.9
	$23.88  to  $29.35		3,689,900			$	24.65		4.2		3,382,630		$	24.23	4
	$34.88  to  $37.46		2,271,440			$	36.48		8.6		197,920		$	35.19	8.1
			8,089,710			$	26.84		5.4		5,708,920		$	23.16	4.1
	The following table summarizes information about our non-vested options during 2013:
	Non-Vested Stock Options		Number of Options			Weighted- Average Fair Value
	Non-Vested as of January 1, 2013		1,702,275			$	3.31
	Granted		1,418,560			$	3.45
	Vested		(730,015	)		$	3.34
	Forfeited		(10,030	)		$	3.37
	Non-Vested as of December 31, 2013		2,380,790			$	3.38
	As of December 31, 2013, total compensation costs related to non-vested stock options not yet recognized was approximately $2.0 million, which is expected to be recognized over the next 21 months on a weighted-average basis.
	Restricted Shares:   The Compensation Committee has also approved restricted stock grants to certain key employees and directors. The following restricted stock activity occurred during 2013:
	Restricted Shares		Number of Shares			Weighted-Average Market Price
	Outstanding as of January 1, 2013		188,222
	Granted		74,290			$	37.65
	Released		(97,973	)		$	26.65
	Forfeited		(13,841	)		$	33.35
	Outstanding as of December 31, 2013		150,698
	In January 2014, the Compensation Committee awarded 71,504 restricted shares to our directors, officers and other key employees under its normal schedule of awarding long-term incentive compensation. These awards have a three-year vesting period, and generally, one-third of the award vests on each anniversary of the grant date. During the vesting period, restricted share recipients also have voting rights and are entitled to dividends in the same manner as other shareholders.
	We record the market value of the restricted stock awards on the date of grant and then we charge their value to expense over the vesting period of the awards. The intrinsic value of restricted stock vesting was $4.0 million, $3.5 million and $2.5 million for the years ended December 31, 2013, 2012, and 2011, respectively. The actual tax benefit realized for the tax deductions from released restricted shares for the same years was $1.3 million, zero and $0.8 million, respectively.
	As of December 31, 2013, total compensation cost related to restricted stock not yet recognized was approximately $2.6 million, which is expected to be recognized over the next 20 months on a weighted-average basis.
	Performance Units:   In January 2013, 2012 and 2011, the Compensation Committee awarded 239,120, 346,570 and 435,690 performance units, respectively, to officers and other key employees under the Wisconsin Energy Performance Unit Plan. Under the grants, the ultimate number of units that will be awarded is dependent upon the achievement of certain financial performance of our stock over a three-year period. Under the terms of the award, participants may earn between 0% and 175% of the base performance unit award. All grants are settled in cash. We are accruing compensation costs over the three-year performance period based on our estimate of the final expected value of the awards. Performance units earned as of December 31, 2013, 2012 and 2011 vested and were settled during the first quarter of 2014, 2013 and 2012, and had a total intrinsic value of $14.8 million, $19.3 million and $26.7 million, respectively. The actual tax benefit realized for the tax deductions from the distribution of performance units was approximately $5.3 million, $7.0 million and $9.7 million, respectively.
	In January 2014, the Compensation Committee awarded 233,735 performance units to our officers and other key employees under its normal schedule of awarding long-term incentive compensation.
	As of December 31, 2013, total compensation cost related to performance units not yet recognized was approximately $10.8 million, which is expected to be recognized over the next 20 months on a weighted-average basis.
	Restrictions:   Wisconsin Energy's ability as a holding company to pay common dividends primarily depends on the availability of funds received from its non-utility subsidiary, We Power, and its utility subsidiaries.
	Various financing arrangements and regulatory requirements impose certain restrictions on the ability of our subsidiaries to transfer funds to Wisconsin Energy in the form of cash dividends, loans or advances. In addition, under Wisconsin law, Wisconsin Electric and Wisconsin Gas are prohibited from loaning funds, either directly or indirectly, to Wisconsin Energy.
	Wisconsin Electric and Wisconsin Gas are required to maintain capital structures that differ from GAAP as they reflect regulatory adjustments. The 2013 PSCW rate case order requires Wisconsin Electric to maintain a common equity ratio range of between 48.5% and 53.5%, and Wisconsin Gas to maintain a capital structure which has a common equity range of between 45.0% and 50.0%. Each company is in compliance with its respective common equity range. Wisconsin Electric and Wisconsin Gas must obtain PSCW approval if they pay dividends above the test year levels that would cause either company to fall below the authorized levels of common equity.
	Wisconsin Electric may not pay common dividends to Wisconsin Energy under Wisconsin Electric's Restated Articles of Incorporation if any dividends on Wisconsin Electric's outstanding preferred stock have not been paid. In addition, pursuant to the terms of Wisconsin Electric's 3.60% Serial Preferred Stock, Wisconsin Electric's ability to declare common dividends would be limited to 75% or 50% of net income during a twelve month period if Wisconsin Electric's common stock equity to total capitalization, as defined in the preferred stock designation, is less than 25% and 20%, respectively.
	We have the option to defer interest payments on the Junior Notes, from time to time, for one or more periods of up to 10 consecutive years per period. During any period in which we defer interest payments, we may not declare or pay any dividends or distributions on, or redeem, repurchase or acquire, our common stock.
	As of December 31, 2013, the restricted net assets of consolidated and unconsolidated subsidiaries and our equity in undistributed earnings of 50% or less owned investees accounted for by the equity method total approximately $3.6 billion. This amount exceeds 25% of our consolidated net assets as of December 31, 2013.
	See Note K for discussion of certain financial covenants related to the bank back-up credit facilities of Wisconsin Energy, Wisconsin Electric and Wisconsin Gas.
	We do not believe that these restrictions will materially affect our operations or limit any dividend payments in the foreseeable future.
	Share Repurchase Program:   We do not expect to issue new shares under our various employee benefit plans and our dividend reinvestment and share purchase plan; rather, we instruct independent plan agents to purchase the shares in the open market. In that regard, no new shares of common stock were issued in 2013, 2012 or 2011.
	In May 2011, our Board of Directors authorized a share repurchase program for up to $300 million of our common stock through the end of 2013. Through December 31, 2013, we repurchased approximately 7.7 million shares pursuant to this program at an average cost of $36.19 per share and a total cost of $277.8 million. In addition, through our independent agents, we purchase shares on the open market to fulfill exercised stock options and restricted stock awards. The following table identifies the shares purchased by the Company for the year ending December 31:
		2013						2012						2011
	Shares			Cost			Shares			Cost			Shares	Cost
	(In Millions)
Under May 2011 share repurchase program	3			$	126		1.5			$	51.8		3.2	$	100
To fulfill exercised stock options and restricted stock awards	2.4			97.4			2.8			101.4			3	93.9
Total	5.4			$	223.4		4.3			$	153.2		6.2	$	193.9
On December 5, 2013, our Board of Directors authorized a new share repurchase program for management to purchase up to $300 million of the Company's common stock through open market purchases or privately negotiated transactions from January 1, 2014 through the end of 2017. The repurchase program does not obligate Wisconsin Energy to acquire any specific number of shares and may be suspended or terminated by the Board of Directors at any time.

LongTerm_Debt_and_Capital_Leas

Long-Term Debt and Capital Lease Obligations	12 Months Ended
	Dec. 31, 2013
Long-term Debt and Capital Lease Obligations [Abstract]	'
LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS	'
	LONG-TERM DEBT AND CAPITAL LEASE OBLIGATIONS
	Debentures and Notes:   As of December 31, 2013, the maturities and sinking fund requirements of our long-term debt outstanding (excluding obligations under capital leases) were as follows:
		(Millions of Dollars)
	2014	$	322.4
	2015	399.5
	2016	27.4
	2017	29.5
	2018	281.1
	Thereafter	3,566.80
	Total	$	4,626.70
	We amortize debt premiums, discounts and debt issuance costs over the lives of the debt and we include the costs in interest expense.
	Wisconsin Electric is the obligor under two series of tax-exempt pollution control refunding bonds in outstanding principal amount of $147 million. In August 2009, Wisconsin Electric terminated letters of credit that provided credit and liquidity support for the bonds, which resulted in a mandatory tender of the bonds. Wisconsin Electric purchased the bonds at par plus accrued interest to the date of purchase. As of December 31, 2013 and 2012, the repurchased bonds were still outstanding, but were not reported in our consolidated long-term debt because they are held by Wisconsin Electric. Depending on market conditions and other factors, Wisconsin Electric may change the method used to determine the interest rate on the bonds and have them remarketed to third parties.
	In connection with our outstanding Junior Notes, we executed the Replacement Capital Covenant dated May 11, 2007 (RCC) for the benefit of persons that buy, hold or sell a specified series of long-term indebtedness (covered debt). Our 6.20% Senior Notes due April 1, 2033 have been designated as the covered debt under the RCC. The RCC provides that we may not redeem, defease or purchase and our subsidiaries may not purchase any Junior Notes on or before May 15, 2037, unless, subject to certain limitations described in the RCC, during the 180 days prior to the date of redemption, defeasance or purchase, we have received a specified amount of proceeds from the sale of qualifying securities.
	Obligations Under Capital Leases:   In 1997, Wisconsin Electric entered into a 25-year power purchase contract with an unaffiliated independent power producer. The contract, for 236 MW of firm capacity from a gas-fired cogeneration facility, includes no minimum energy requirements. When the contract expires in 2022, Wisconsin Electric may, at its option and with proper notice, renew for another ten years or purchase the generating facility at fair value or allow the contract to expire. We account for this contract as a capital lease and recorded the leased facility and corresponding obligation under the capital lease at the estimated fair value of the plant's electric generating facilities. We are amortizing the leased facility on a straight-line basis over the original 25-year term of the contract.
	We treat the long-term power purchase contract as an operating lease for rate-making purposes and we record our minimum lease payments as purchased power expense on the Consolidated Income Statements. We paid a total of $33.7 million and $32.5 million in lease payments during 2013 and 2012, respectively. We record the difference between the minimum lease payments and the sum of imputed interest and amortization costs calculated under capital lease accounting as a deferred regulatory asset on our Consolidated Balance Sheets (see Regulatory Assets - Deferred plant related -- capital lease in Note C). Due to the timing and the amounts of the minimum lease payments, the regulatory asset increased to approximately $78.5 million during 2009, at which time the regulatory asset began to be reduced to zero over the remaining life of the contract. The total obligation under the capital lease was $104.3 million as of December 31, 2013, and will decrease to zero over the remaining life of the contract.
	The following is a summary of our capitalized leased facilities as of December 31:
	Capital Lease Assets		2013			2012
			(Millions of Dollars)
	Leased Facilities
	Long-term power purchase commitment		$	140.3		$	140.3
	Accumulated amortization		(92.5		)	(86.8		)
	Total Leased Facilities		$	47.8		$	53.5
	Future minimum lease payments under our capital lease and the present value of our net minimum lease payments as of December 31, 2013 are as follows:
		(Millions of Dollars)
	2014	$	41.9
	2015	43.5
	2016	45.1
	2017	13.9
	2018	14.7
	Thereafter	56.8
	Total Minimum Lease Payments	215.9
	Less:  Estimated Executory Costs	(61.7		)
	Net Minimum Lease Payments	154.2
	Less:  Interest	(49.9		)
	Present Value of Net
	Minimum Lease Payments	104.3
	Less:  Due Currently	(19.8		)
		$	84.5

ShortTerm_Debt

Short-Term Debt	12 Months Ended
	Dec. 31, 2013
Short-term Debt [Abstract]	'
SHORT-TERM DEBT	'
	SHORT-TERM DEBT
	Short-term notes payable balances and their corresponding weighted-average interest rates as of December 31 consist of:
			2013					2012
						Interest				Interest
	Short-Term Debt		Balance			Rate		Balance		Rate
			(Millions of Dollars, except for percentages)
	Commercial paper		$	537.4		0.2	%	$	394.6	0.3	%
	The following information relates to commercial paper for the years ended December 31:
		2013			2012
		(Millions of Dollars, except for percentages)
	Maximum Short-Term Debt Outstanding	$	594.5		$	669.9
	Average Short-Term Debt Outstanding	$	359.1		$	481.6
	Weighted-Average Interest Rate	0.25		%	0.28		%
	Wisconsin Energy, Wisconsin Electric and Wisconsin Gas have entered into bank back-up credit facilities to maintain short-term credit liquidity which, among other terms, require the companies to maintain, subject to certain exclusions, a minimum total funded debt to capitalization ratio of less than 70%, 65% and 65%, respectively.
	As of December 31, 2013, we had approximately $1.2 billion of available undrawn lines under our bank back-up credit facilities and $537.4 million of commercial paper outstanding that was supported by the available lines of credit. Our bank back-up credit facilities expire in December 2017.
	The Wisconsin Energy, Wisconsin Electric and Wisconsin Gas bank back-up credit facilities contain customary covenants, including certain limitations on the respective companies' ability to sell assets. The credit facilities also contain customary events of default, including payment defaults, material inaccuracy of representations and warranties, covenant defaults, bankruptcy proceedings, certain judgments, ERISA defaults and change of control. In addition, pursuant to the terms of Wisconsin Energy's credit agreement, Wisconsin Energy must ensure that certain of its subsidiaries comply with several of the covenants contained therein.
	As of December 31, 2013, we were in compliance with all financial covenants.

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedges, Assets [Abstract]	'
DERIVATIVE INSTRUMENTS	'
	DERIVATIVE INSTRUMENTS
	We utilize derivatives as part of our risk management program to manage the volatility and costs of purchased power, generation and natural gas purchases for the benefit of our customers and shareholders. Our approach is non-speculative and designed to mitigate risk and protect against price volatility. Regulated hedging programs require prior approval by the PSCW.
	We record derivative instruments on the balance sheet as an asset or liability measured at its fair value, and 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, the PSCW allows the effects of the fair market value accounting to be offset to regulatory assets and liabilities. As of December 31, 2013, we recognized $0.3 million in regulatory assets and $9.6 million in regulatory liabilities related to derivatives in comparison to $7.6 million in regulatory assets and $17.5 million in regulatory liabilities as of December 31, 2012.
	We record our current derivative assets on the balance sheet in other current assets and the current portion of the liabilities in other current liabilities. The long-term portion of our derivative assets of $0.4 million is recorded in other deferred charges and other assets, and we had no long-term portion of derivative liabilities. Our Consolidated Balance Sheets as of December 31, 2013 and 2012 include:
		December 31, 2013							December 31, 2012
		Derivative				Derivative			Derivative			Derivative
		Asset				Liability			Asset			Liability
		(Millions of Dollars)
	Natural Gas	$	5.6			$	0.1		$	3		$	1.9
	Fuel Oil	0.6				—			0.4			—
	FTRs	3.5				—			4.7			—
	Coal	2.1				0.2			11.1			—
	Total	$	11.8			$	0.3		$	19.2		$	1.9
	Our Consolidated Income Statements include gains (losses) on derivative instruments used in our risk management strategies under fuel and purchased power for those commodities supporting our electric operations and under cost of gas sold for the natural gas sold to our customers. Our estimated notional volumes and gains (losses) for the years ended December 31 were as follows:
		2013						2012
		Volume		Gains (Losses)				Volume	Gains (Losses)
				(Millions of Dollars)					(Millions of Dollars)
	Natural Gas	48.6 million Dth		$	(8.5	)		77.2 million Dth	$	(36.3	)
	Fuel Oil	8.6 million gallons		0.5				7.0 million gallons	1.8
	FTRs	25.3 million MWh		14.9				25.1 million MWh	6.1
	Total			$	6.9				$	(28.4	)
	As of December 31, 2013 and 2012, we posted collateral of zero and $2.9 million, respectively, in our margin accounts. These amounts are recorded on the balance sheets in other current assets.
	The fair value 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. The table below shows derivative assets and derivative liabilities if derivative instruments by counterparty were presented net on the balance sheet as of December 31, 2013 and 2012.
		2013							2012
		Derivative				Derivative			Derivative			Derivative
		Asset				Liability			Asset			Liability
		(Millions of Dollars)
	Gross Amount Recognized on the Balance Sheet	$	11.8			$	0.3		$	19.2		$	1.9
	Gross Amount Not Offset on Balance Sheet (a)	—				—			(0.5		)	(1.8		)
	Net Amount	$	11.8			$	0.3		$	18.7		$	0.1
	(a)	Gross Amount Not Offset on Balance Sheet includes cash collateral posted of zero and $1.3 million as of December 31, 2013 and 2012, respectively.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Measurements [Abstract]	'
FAIR VALUE MEASUREMENTS	'
	FAIR VALUE MEASUREMENTS
	Fair value measurements require enhanced disclosures about assets and liabilities that are measured and reported at fair value and establish a hierarchal disclosure framework which prioritizes and ranks the level of observable inputs used in measuring fair value.
	Fair value is the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We primarily apply the market approach for recurring fair value measurements and attempt to utilize the best available information. Accordingly, we also utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. We are able to classify fair value balances based on the observability of those inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3).
	Assets and liabilities measured and reported at fair value are classified and disclosed in one of the following categories:
	Level 1 -- Pricing inputs are unadjusted quoted prices 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. Instruments in this category consist of financial instruments such as exchange-traded derivatives, cash equivalents and restricted cash investments.
	Level 2 -- Pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date, and fair value is determined through the use of models or other valuation methodologies. Instruments in this category include non-exchange-traded derivatives such as OTC forwards and options.
	Level 3 -- Pricing inputs include significant inputs that are generally less observable from objective sources. The inputs in the determination of fair value require significant management judgment or estimation. At each balance sheet date, we perform an analysis of all instruments subject to fair value reporting and include in Level 3 all instruments whose fair value is based on significant unobservable inputs.
	In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an instrument's level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the instrument.
	The following tables summarize our financial assets and liabilities by level within the fair value hierarchy:
	Recurring Fair Value Measures		As of December 31, 2013
			Level 1			Level 2		Level 3		Total
			(Millions of Dollars)
	Assets:
	Derivatives		$	5.7		$	2.6	$	3.5	11.8
	Total		$	5.7		$	2.6	$	3.5	$	11.8
	Liabilities:
	Derivatives		$	—		$	0.3	$	—	$	0.3
	Total		$	—		$	0.3	$	—	$	0.3
	Recurring Fair Value Measures		As of December 31, 2012
			Level 1			Level 2		Level 3		Total
			(Millions of Dollars)
	Assets:
	Restricted Cash		$	2.7		$	—	$	—	$	2.7
	Derivatives		2.2			12.3		4.7		19.2
	Total		$	4.9		$	12.3	$	4.7	$	21.9
	Liabilities:
	Derivatives		$	1.9		$	—	$	—	$	1.9
	Total		$	1.9		$	—	$	—	$	1.9
	We adopted ASU 2013-01, Disclosures about Offsetting Assets and Liabilities, on a retrospective basis. For additional information, see Note B -- Recent Accounting Pronouncements and Note L -- Derivative Instruments.
	Restricted cash consists of certificates of deposit and government backed interest bearing securities and represents the settlement we received from the DOE during the first quarter of 2011, which was returned, net of costs incurred, to customers. Derivatives reflect positions we hold in exchange-traded derivative contracts and OTC derivative contracts. Exchange-traded derivative contracts, which include futures and exchange-traded options, are generally based on unadjusted quoted prices in active markets and are classified within Level 1. Some OTC derivative contracts are valued using broker or dealer quotations, or market transactions in either the listed or OTC markets utilizing a mid-market pricing convention (the mid-point between bid and ask prices), as appropriate. In such cases, these derivatives are classified within Level 2. Certain OTC derivatives may utilize models to measure fair value. Generally, we use a similar model to value similar instruments. Valuation models utilize various inputs which include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, other observable inputs for the asset or liability, and market-corroborated inputs (i.e., inputs derived principally from or corroborated by observable market data by correlation or other means). Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized in Level 2. Certain OTC derivatives are in less active markets with a lower availability of pricing information which might not be observable in or corroborated by the market. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized in Level 3.
	The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy:
		2013			2012
		(Millions of Dollars)
	Balance as of January 1	$	4.7		$	5.7
	Realized and unrealized gains (losses)	—			—
	Purchases	10.6			11
	Issuances	—			—
	Settlements	(11.8		)	(12.0		)
	Transfers in and/or out of Level 3	—			—
	Balance as of December 31	$	3.5		$	4.7
	Change in unrealized gains (losses) relating to instruments still held as of December 31	$	—		$	—
	Derivative instruments reflected in Level 3 of the hierarchy include MISO FTRs that are measured at fair value each reporting period using monthly or annual auction shadow prices from relevant auctions. Changes in fair value for Level 3 recurring items are recorded on our balance sheet. See Note L -- Derivative Instruments, for further information on the offset to regulatory assets and liabilities.
	The carrying amount and estimated fair value of certain of our recorded financial instruments as of December 31 are as follows:
			2013					2012
			Carrying			Fair		Carrying		Fair
	Financial Instruments		Amount			Value		Amount		Value
			(Millions of Dollars)
	Preferred stock, no redemption required		$	30.4		$	26	$	30.4	$	26
	Long-term debt including current portion		$	4,626.70		$	4,911.80	$	4,772.90	$	5,447.30
	The carrying value of net accounts receivable, accounts payable and short-term borrowings approximates fair value due to the short-term nature of these instruments. The fair value of our preferred stock is estimated based upon the quoted market value for the same or similar issues. 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 quoted market value for the same or 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.

Benefits

Benefits	12 Months Ended
	Dec. 31, 2013
General Discussion of Pension and Other Postretirement Benefits [Abstract]	'
BENEFITS	'
	- BENEFITS
	Pensions and Other Post-retirement Benefits:   We have defined benefit pension plans that cover substantially all of our employees. Generally, employees who started with the company after 1995 receive a benefit based on a percentage of their annual salary plus an interest credit, while employees who started before 1996 receive a benefit based upon years of service and final average salary. Approximately half of our projected benefit obligation relates to benefits based upon years of service and final average salary.
	We also have OPEB plans covering substantially all of our employees. The health care plans are contributory with participants' contributions adjusted annually; the life insurance plans are noncontributory. The accounting for the health care plans anticipates future cost-sharing changes to the written plans that are consistent with our expressed intent to maintain the current cost sharing levels. The post-retirement health care plans include a limit on our share of costs for recent and future retirees.
	We use a year-end measurement date to measure the funded status of all of our pension and OPEB plans. Due to the regulated nature of our business, we have concluded that substantially all of the unrecognized costs resulting from the recognition of the funded status of our pension and OPEB plans qualify as a regulatory asset.
	The following table presents details about our pension and OPEB plans:
		Pension							OPEB
		2013				2012			2013			2012
		(Millions of Dollars)
	Change in Benefit Obligation
	Benefit Obligation at January 1	$	1,508.50			$	1,330.60		$	381.2		$	389.7
	Service cost	14.6				21.7			10			10.3
	Interest cost	60.4				65.5			15.6			20.3
	Participants' contributions	—				—			8.9			9.6
	Plan amendments	(1.0		)		—			—			0.5
	Actuarial loss (gain)	(81.9		)		166.5			(27.7		)	(23.8		)
	Other accrued benefits	—				31.4			—			—
	Gross benefits paid	(90.4		)		(107.2		)	(26.3		)	(26.3		)
	Federal subsidy on benefits paid	N/A				N/A			1			0.9
	Benefit Obligation at December 31	$	1,410.20			$	1,508.50		$	362.7		$	381.2
	Change in Plan Assets
	Fair Value at January 1	$	1,385.40			$	1,262.50		$	285.4		$	255.4
	Actual earnings on plan assets	147.3				127.4			45.5			29
	Employer contributions	8.7				102.7			14.1			17.7
	Participants' contributions	—				—			8.9			9.6
	Gross benefits paid	(90.4		)		(107.2		)	(26.3		)	(26.3		)
	Fair Value at December 31	$	1,451.00			$	1,385.40		$	327.6		$	285.4
	Net asset (liability)	$	40.8			$	(123.1	)	$	(35.1	)	$	(95.8	)
	As of December 31, 2013, our qualified pension plan was over-funded by $138.7 million and our non-qualified pension plan was under-funded by $97.9 million. As of December 31, 2012, our qualified and non-qualified pension plans were under-funded by $20.9 million and $102.2 million, respectively.
	Amounts recognized in our Consolidated Balance Sheets as of December 31 related to the funded status of the benefit plans consisted of:
		Pension							OPEB
		2013				2012			2013			2012
		(Millions of Dollars)
	Other long-term assets	$	138.7			$	—		$	40.2		$	25.1
	Other long-term liabilities	$	97.9			$	123.1		$	75.3		$	120.9
	The accumulated benefit obligation for all defined pension plans was $1,409.5 million and $1,507.1 million as of December 31, 2013, and 2012, respectively.
	The following table shows the amounts that have not yet been recognized in our net periodic benefit cost as of December 31 and are recorded as a regulatory asset on our balance sheet:
		Pension							OPEB
		2013				2012			2013			2012
		(Millions of Dollars)
	Net actuarial loss	$	528.8			$	719.2		$	9.8		$	65.3
	Prior service costs (credits)	8.8				12.2			(1.7		)	(3.7		)
	Total - Regulatory Assets	$	537.6			$	731.4		$	8.1		$	61.6
	We estimate that 2014 periodic pension and OPEB costs will include the amortization of previously unrecognized benefit costs (credits) referred to above of $38.7 million and $(0.9) million, respectively.
	The components of net periodic pension and OPEB costs for the years ended December 31 are as follows:
		Pension										OPEB
		2013				2012			2011			2013			2012			2011
		(Millions of Dollars)
	Net Periodic Benefit Cost
	Service cost	$	14.6			$	21.7		$	15.9		$	10		$	10.3		$	10.4
	Interest cost	60.4				65.5			67.6			15.6			20.3			20.8
	Expected return on plan assets	(95.8		)		(89.6		)	(82.1		)	(21.3		)	(19.0		)	(16.9		)
	Amortization of:
	Transition obligation	—				—			—			—			0.3			0.3
	Prior service cost (credit)	2.3				2.2			2.2			(2.0		)	(1.9		)	(1.9		)
	Actuarial loss	54.5				41			34			3.7			7.3			6.2
	Settlement charge	2.5				—			—			—			—			—
	Other	—				0.4			—			—			—			—
	Net Periodic Benefit Cost	$	38.5			$	41.2		$	37.6		$	6		$	17.3		$	18.9
		Pension						OPEB
		2013		2012		2011		2013	2012		2011
	Weighted-Average assumptions used to
	determine benefit obligations as of Dec. 31
	Discount rate	5.00%		4.10%		5.05%		4.95%	4.15%		5.20%
Rate of compensation increase	4.00%		4.00%		4.00%		N/A	N/A		N/A
Weighted-Average assumptions used to
determine net cost for year ended Dec. 31
Discount rate	4.10%		5.05%		5.60%		4.15%	5.20%		5.70%
Expected return on plan assets	7.25%		7.25%		7.25%		7.50%	7.50%		7.50%
Rate of compensation increase	4.00%		4.00%		4.00%		N/A	N/A		N/A
Assumed health care cost trend rates as of Dec. 31		2013		2012		2011
Health care cost trend rate assumed for next year (Pre 65 / Post 65)		7.5%/7.5%		7.5%/7.5%		8.0%/12%
Rate that the cost trend rate gradually adjusts to		5.00%		5.00%		5.00%
Year that the rate reaches the rate it is assumed to remain at (Pre 65 / Post 65)		2021/2021		2017/2017		2017/2017
The expected long-term rate of return on pension and OPEB plan assets was 7.25% and 7.50%, respectively, in 2013, 2012 and 2011. We consult with our investment advisors on an annual basis to help us forecast expected long-term returns on plan assets by reviewing historical returns as well as calculating expected total trust returns using the weighted-average of long-term market returns for each of the major target asset categories utilized in the fund.
A one-percentage-point change in assumed health care cost trend rates would have the following effects:
	1% Increase				1% Decrease
	(Millions of Dollars)
Effect on
Post-retirement benefit obligation	$	26.4			$	(22.3	)
Total of service and interest cost components	$	3.2			$	(2.6	)
We use various Employees' Benefit Trusts to fund a major portion of OPEB. The majority of the trusts' assets are mutual funds.
Plan Assets:   Current pension trust assets and amounts which are expected to be contributed to the trusts in the future are expected to be adequate to meet pension payment obligations to current and future retirees.
The Investment Trust Policy Committee oversees investment matters related to all of our funded benefit plans. The Committee works with external actuaries and investment consultants on an on-going basis to establish and monitor investment strategies and target asset allocations. Forecasted cash flows for plan liabilities are regularly updated based on annual valuation results. Target allocations are determined utilizing projected benefit payment cash flows and risk analyses of appropriate investments. They are intended to reduce risk, provide long-term financial stability for the plans and maintain funded levels which meet long-term plan obligations while preserving sufficient liquidity for near-term benefit payments.
Our current pension plan target asset allocation is 45% equity investments and 55% fixed income investments. The current OPEB target asset allocation is 60% equity investments and 40% fixed income investments. Equity securities include investments in large-cap, mid-cap and small-cap companies primarily located in the United States. Fixed income securities include corporate bonds of companies from diversified industries, mortgage and other asset backed securities, commercial paper, and U.S. Treasuries.
The following table summarizes the fair value of our pension plan assets by asset category within the fair value hierarchy (for further level information, see Note M):
		As of December 31, 2013
Asset Category - Pension		Level 1				Level 2			Level 3			Total
		(Millions of Dollars)
Cash and Cash Equivalents		$	21			$	—		$	—		$	21
Equities:
U.S. Equity		519.5				—			—			519.5
International Equity		146.2				35.7			—			181.9
Fixed Income
Short, Intermediate and Long-term Bonds (a)
U.S. Bonds		108.4				505.2			—			613.6
International Bonds		78.1				36.9			—			115
Total		$	873.2			$	577.8		$	—		$	1,451.00
		As of December 31, 2012
Asset Category - Pension		Level 1				Level 2			Level 3			Total
		(Millions of Dollars)
Cash and Cash Equivalents		$	13.7			$	—		$	—		$	13.7
Equities:
U.S. Equity		466.3				—			—			466.3
International Equity		134.7				30.4			—			165.1
Fixed Income
Short, Intermediate and Long-term Bonds (a)
U.S. Bonds		67.7				546.6			—			614.3
International Bonds		80.7				45.3			—			126
Total		$	763.1			$	622.3		$	—		$	1,385.40
(a)	This category represents investment grade bonds of U.S. and foreign issuers denominated in U.S. dollars from diverse industries.
The following table summarizes the fair value of our OPEB plan assets by asset category within the fair value hierarchy:
		As of December 31, 2013
Asset Category - OPEB		Level 1				Level 2			Level 3			Total
		(Millions of Dollars)
Cash and Cash Equivalents		$	2.6			$	—		$	—		$	2.6
Equities:
U.S. Equity		148				—			—			148
International Equity		46.9				2.8			—			49.7
Fixed Income:
Short, Intermediate and Long-term Bonds (a)
U.S. Bonds		8.4				96.3			—			104.7
International Bonds		16.8				5.8			—			22.6
Total		$	222.7			$	104.9		$	—		$	327.6
		As of December 31, 2012
Asset Category - OPEB		Level 1				Level 2			Level 3			Total
		(Millions of Dollars)
Cash and Cash Equivalents		$	1.7			$	—		$	—		$	1.7
Equities:
U.S. Equity		125.9				—			—			125.9
International Equity		39.9				2.2			—			42.1
Fixed Income:
Short, Intermediate and Long-term Bonds (a)
U.S. Bonds		5				89.9			—			94.9
International Bonds		15.4				5.4			—			20.8
Total		$	187.9			$	97.5		$	—		$	285.4
(a)	This category represents investment grade bonds of U.S. and foreign issuers denominated in U.S. dollars from diverse industries.
Cash Flows:
Historical employer contributions:
		Pension
Year		Qualified				Non-Qualified			OPEB
		(Millions of Dollars)
2011		$	236.4			$	6.5		$	48.4
2012		$	95.6			$	7.1		$	17.7
2013		$	—			$	8.7		$	14.1
Estimated benefit payments:
Year		Pension				Gross OPEB
		(Millions of Dollars)
2014		$	103.9			$	24.2
2015		$	98.6			$	21.6
2016		$	100.3			$	22
2017		$	100.9			$	22.6
2018		$	100.2			$	23.4
2019-2023		$	495.6			$	119.7
Savings Plans:   We sponsor savings plans which allow employees to contribute a portion of their pre-tax and/or after-tax income in accordance with plan-specified guidelines. Under these plans, we expensed matching contributions of $14.2 million, $13.8 million and $14.1 million during 2013, 2012 and 2011, respectively.
Postemployment Benefits:   Postemployment benefits provided to former or inactive employees are recognized when an event occurs. The estimated liability for such benefits was $4.2 million and $4.0 million as of December 31, 2013 and 2012, respectively.

Segment_Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
SEGMENT REPORTING	'
	SEGMENT REPORTING
	Our reportable segments as of December 31, 2013 include a utility energy segment and a non-utility energy segment. We have organized our reportable segments based upon the regulatory environment in which our utility subsidiaries operate and on how management makes decisions and measures performance. The segments are managed separately because each business requires different technology and marketing strategies. The accounting policies of the reportable operating segments are the same as those described in Note A.
	Our utility energy segment primarily includes our electric and natural gas utility operations. Our electric utility operation engages in the generation, distribution and sale of electric energy in southeastern (including metropolitan Milwaukee), east central and northern Wisconsin and in the Upper Peninsula of Michigan. Our natural gas utility operation is engaged in the purchase, distribution and sale of natural gas to retail customers and the transportation of customer-owned natural gas throughout Wisconsin. Our non-utility energy segment derives its revenues primarily from the ownership of electric power generating facilities for long-term lease to Wisconsin Electric.
	Summarized financial information concerning our reportable segments for each of the three years ended December 31, 2013 is shown in the following table.
			Reportable Segments							Eliminations
			Energy				Corporate &			& Reconciling			Total
	Year Ended		Utility		Non-Utility		Other (a)			Items			Consolidated
			(Millions of Dollars)
	December 31, 2013
	Operating Revenues (b)		$	4,462.00	$	446.7	$	1.3		$	(391.0	)	$	4,519.00
	Depreciation and Amortization		$	320.2	$	67.1	$	0.8		$	—		$	388.1
	Operating Income (Loss)		$	719.4	$	367.1	$	(6.4	)	$	—		$	1,080.10
	Equity in Earnings of Unconsolidated Affiliates		$	68.5	$	—	$	(0.1	)	$	—		$	68.4
	Interest Expense, Net		$	136.2	$	65.7	$	50.8		$	(0.6	)	$	252.1
	Income Tax Expense (Benefit)		$	243.6	$	120.2	$	(25.9	)	$	—		$	337.9
	Net Income (Loss)		$	425.1	$	181.6	$	577.2		$	(606.5	)	$	577.4
	Capital Expenditures		$	657.9	$	26.1	$	3.4		$	—		$	687.4
	Total Assets (c)		$	14,460.40	$	2,846.50	$	4,719.50		$	(7,257.0	)	$	14,769.40
	December 31, 2012
	Operating Revenues (b)		$	4,190.80	$	439.9	$	1.2		$	(385.5	)	$	4,246.40
	Depreciation and Amortization		$	296.4	$	67.1	$	0.7		$	—		$	364.2
	Operating Income (Loss)		$	647.7	$	358.8	$	(6.2	)	$	—		$	1,000.30
	Equity in Earnings of Unconsolidated Affiliates		$	65.7	$	—	$	(0.2	)	$	—		$	65.5
	Interest Expense, Net		$	129.4	$	66.7	$	52.5		$	(0.4	)	$	248.2
	Income Tax Expense (Benefit)		$	214.9	$	116.6	$	(25.2	)	$	—		$	306.3
	Net Income (Loss)		$	400.6	$	175.9	$	546.1		$	(576.3	)	$	546.3
	Capital Expenditures		$	697.3	$	5.5	$	4.2		$	—		$	707
	Total Assets (c)		$	13,988.10	$	2,903.50	$	4,431.40		$	(7,038.0	)	$	14,285.00
	December 31, 2011
	Operating Revenues (b)		$	4,431.50	$	435.1	$	0.9		$	(381.1	)	$	4,486.40
	Depreciation and Amortization		$	257	$	72.5	$	0.7		$	—		$	330.2
	Operating Income (Loss)		$	544.8	$	348.9	$	(6.4	)	$	—		$	887.3
	Equity in Earnings of Unconsolidated Affiliates		$	62.5	$	—	$	(0.9	)	$	—		$	61.6
	Interest Expense, Net		$	110	$	66.7	$	59.5		$	(0.4	)	$	235.8
	Income Tax Expense (Benefit)		$	182.7	$	112.8	$	(31.6	)	$	—		$	263.9
	Income from Discontinued Operations, Net of Tax		$	—	$	—	$	13.4		$	—		$	13.4
	Net Income (Loss)		$	376.3	$	169.8	$	525.9		$	(545.8	)	$	526.2
	Capital Expenditures		$	792.2	$	31.2	$	7.4		$	—		$	830.8
	Total Assets (c)		$	13,433.50	$	2,949.00	$	4,694.80		$	(7,215.2	)	$	13,862.10
	(a)	Corporate & Other includes all other non-utility activities, primarily non-utility real estate investment and development by Wispark as well as interest on corporate debt.
	(b)	An elimination for intersegment revenues is included in Operating Revenues. This elimination is primarily between We Power and Wisconsin Electric.
	(c)	An elimination of $2,231.2 million, $2,286.7 million and $2,369.0 million is included in Total Assets as of December 31, 2013, 2012 and 2011, respectively, for all PTF-related activity between We Power and Wisconsin Electric.

Related_Parties

Related Parties	12 Months Ended
	Dec. 31, 2013
Related Party Transaction, Due from (to) Related Party [Abstract]	'
Provided and received services from the associated companies	'
	RELATED PARTIES
	We receive and/or provide certain services to other associated companies in which we have an equity investment.
	American Transmission Company LLC:   As of December 31, 2013, we have a 26.2% interest in ATC. We pay ATC for transmission and other related services it provides. In addition, we provide a variety of operational, maintenance and project management work for ATC, which is reimbursed to us by ATC. We are required to pay the cost of needed transmission infrastructure upgrades for new generation projects while projects are under construction, including the generating units constructed as part of our PTF strategy. ATC reimburses us for these costs when new generation is placed in service.
	The following table summarizes material related party transactions with ATC during 2013, 2012 and 2011:
	Equity Investee	2013		2012		2011
		(Millions of Dollars)
	Equity in Earnings	$	68.5	$	65.7	$	62.5
	Distributions Received	$	54.5	$	52.6	$	49.7
	Services Provided	$	9	$	8.2	$	10.8
	Services Received	$	234.2	$	222.7	$	219.2
	As of December 31, 2013 and 2012, our Consolidated Balance Sheets included receivable and payable balances with ATC as follows:
	Equity Investee	2013		2012
		(Millions of Dollars)
	Accounts Receivable
	Services provided	$	0.6	$	0.5
	Accounts Payable
	Services received	$	19.5	$	18.6

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies [Abstract]	'
COMMITMENTS AND CONTINGENCIES	'
	COMMITMENTS AND CONTINGENCIES
	Operating Leases:   We enter into long-term purchase power contracts to meet a portion of our anticipated increase in future electric energy supply needs. These contracts expire at various times through 2018. Certain of these contracts were deemed to qualify as operating leases. In addition, we have various other operating leases including leases for coal cars.
	Future minimum payments for the next five years and thereafter for our operating lease contracts are as follows:
		(Millions of Dollars)
	2014	$	3.9
	2015	3.9
	2016	3.7
	2017	3.1
	2018	3.2
	Thereafter	22.7
	Total	$	40.5
	Divested Assets:   Pursuant to the sale of Point Beach, we have agreed to indemnification provisions customary to transactions involving the sale of nuclear assets. We also provided customary indemnifications to WPL in connection with the sale of our interest in Edgewater Generating Unit 5.
	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 sites. We perform ongoing assessments of manufactured gas plant sites and related disposal sites used by Wisconsin Electric and Wisconsin Gas, and coal combustion product disposal/landfill sites used by Wisconsin Electric, as discussed below. We are working with the WDNR in our investigation and remediation planning. At this time, we cannot estimate future remediation costs associated with these sites beyond those described below.
	Manufactured Gas Plant Sites:   We have identified several sites at which Wisconsin Electric, Wisconsin Gas, or a predecessor company historically owned or operated a manufactured gas plant. These sites have been substantially remediated or are at various stages of investigation, monitoring and remediation. We have also identified other sites that may have been impacted by historical manufactured gas plant activities. Based upon on-going analysis, we estimate that the future costs for detailed site investigation and future remediation costs may range from $19 million to $56 million over the next ten years. This estimate is dependent upon several variables including, among other things, the extent of remediation, changes in technology and changes in regulation. As of December 31, 2013 and 2012, we established reserves of $36.9 million and $38.2 million, respectively, related to future remediation costs.
	Historically, the PSCW has allowed Wisconsin utilities, including Wisconsin Electric and Wisconsin Gas, to defer the costs spent on the remediation of manufactured gas plant sites, and has allowed for these costs to be recovered in rates over five years. Accordingly, we have recorded a regulatory asset for remediation costs.
	Coal Combustion Product Landfill Sites:   Wisconsin Electric aggressively seeks environmentally acceptable, beneficial uses for its coal combustion products. However, some coal combustion products have been, and to a small degree continue to be, managed in company-owned, licensed landfills. Some early designed and constructed landfills have at times required various levels of monitoring or remediation. Where Wisconsin Electric has become aware of these conditions, efforts have been made to define the nature and extent of any release, and work has been performed to address these conditions. During 2013, 2012 and 2011, Wisconsin Electric incurred $0.1 million, $0.3 million and $0.2 million respectively, in landfill remediation expenses. As of December 31, 2013, we have no reserves established related to coal combustion product landfill sites.
	Valley Power Plant Title V Air Permit:   The WDNR renewed VAPP's Title V operating permit in February 2011. The term of the permit is five years. Sierra Club and Clean Wisconsin requested and were granted an administrative hearing before the WDNR on certain conditions of the permit; however, the case has been stayed. In addition, in March 2011, the Sierra Club petitioned the EPA for additional reductions and monitoring for particulate matter and revisions to certain applicable requirements. No timeline has been set by the EPA to respond to that petition. In May 2012, the Sierra Club filed a notice of intent to bring suit to force the EPA to issue a response to that petition. We believe that the permit was properly issued and that the plant is in compliance with all applicable regulations and standards. However, if as a result of either proceeding the permit is remanded to the WDNR, the plant will continue to operate under the previous operating permit.
	In August 2012, we announced plans to convert the fuel source for VAPP from coal to natural gas and anticipate that the conversion will be completed by the end of 2015 or early 2016. We currently expect the cost of this conversion to be between $65 million and $70 million, excluding AFUDC. We filed for a Certificate of Authority from the PSCW on April 26, 2013, and received preliminary approval on January 30, 2014. We expect to receive a final written order by the end of the first quarter. We received a construction air permit from the WDNR on November 11, 2013.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]	'
SUPPLEMENTAL CASH FLOW INFORMATION	'
	SUPPLEMENTAL CASH FLOW INFORMATION
	During the year ended December 31, 2013, we paid $250.4 million in interest, net of amounts capitalized, and received $39.6 million in net refunds from income taxes. During the year ended December 31, 2012, we paid $241.2 million in interest, net of amounts capitalized, and received $107.0 million in net refunds from income taxes. During the year ended December 31, 2011, we paid $234.0 million in interest, net of amounts capitalized, and received $109.1 million in net refunds from income taxes.
	As of December 31, 2013, 2012 and 2011, the amount of accounts payable related to capital expenditures was $4.7 million, $15.7 million and $16.7 million, respectively.
	During the years ended December 31, 2013, 2012 and 2011, total amortization of deferred revenue was $56.5 million, $54.9 million and $54.4 million, respectively.

Schedule_I_Condensed_Parent_Co

Schedule I -- Condensed Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2013
Schedule I -- Condensed Parent Company Financial Statements [Abstract]	'
SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS	'
	WISCONSIN ENERGY CORPORATION
	INCOME STATEMENTS
	(Parent Company Only)
	SCHEDULE I -- CONDENSED PARENT COMPANY
	FINANCIAL STATEMENTS
		Year Ended December 31
		2013			2012			2011
		(Millions of Dollars)
	Other Income, Net	$	3.1		$	3.2		$	2.7
	Corporate Expense	5.5			4.8			4.8
	Interest Expense	54.4			55.7			61.8
	Loss before Taxes	(56.8		)	(57.3		)	(63.9		)
	Income Tax Benefit	26.4			26			30.8
	Loss after Taxes	(30.4		)	(31.3		)	(33.1		)
	Equity in Subsidiaries' Continuing Operations	607.8			577.6			545.9
	Income from Continuing Operations	577.4			546.3			512.8
	Income from Discontinued Operations including Equity in Subsidiaries' Discontinued Operations	—			—			13.4
	Net Income	$	577.4		$	546.3		$	526.2
	See accompanying notes to condensed parent company financial statements.
	WISCONSIN ENERGY CORPORATION
	STATEMENTS OF CASH FLOWS
	(Parent Company Only)
	SCHEDULE I - CONDENSED PARENT COMPANY
	FINANCIAL STATEMENTS - (Cont'd)
		Year Ended December 31
		2013			2012			2011
		(Millions of Dollars)
	Operating Activities
	Net income	$	577.4		$	546.3		$	526.2
	Reconciliation to cash
	Equity in subsidiaries' earnings	(607.8		)	(577.6		)	(545.9		)
	Dividends and distributions from subsidiaries	720.4			842.3			995.5
	Deferred income taxes, net	(7.8		)	104.4			(350.9		)
	Accrued income taxes, net	66.8			(457.9		)	363.4
	Change in - Other current assets	(0.1		)	0.2			(0.1		)
	Change in - Other current liabilities	(22.9		)	(6.7		)	8.9
	Change in - Accounts receivable	(2.7		)	22.5			(18.7		)
	Other, net	(21.6		)	(8.1		)	(10.2		)
	Cash Provided by Operating Activities	701.7			465.4			968.2
	Investing Activities
	Capital contributions to associated companies	(195.3		)	(21.5		)	(36.5		)
	Capitalized interest and other	4			12.6			2.4
	Cash Used in Investing Activities	(191.3		)	(8.9		)	(34.1		)
	Financing Activities
	Exercise of stock options	48.5			49.8			54.4
	Purchase of common stock	(223.4		)	(153.9		)	(193.9		)
	Dividends paid on common stock	(328.9		)	(276.3		)	(242.0		)
	Retirement of long-term debt	—			—			(450.0		)
	Change in short-term debt	5			(79.5		)	(116.5		)
	Change in notes payable due associated companies	(26.8		)	3.8			3.9
	Other, net	14.6			—			9.9
	Cash Used in Financing Activities	(511.0		)	(456.1		)	(934.2		)
	Change in Cash and Cash Equivalents	(0.6		)	0.4			(0.1		)
	Cash and Cash Equivalents at Beginning of Year	0.9			0.5			0.6
	Cash and Cash Equivalents at End of Year	$	0.3		$	0.9		$	0.5
	See accompanying notes to condensed parent company financial statements.
	WISCONSIN ENERGY CORPORATION
	BALANCE SHEETS
	(Parent Company Only)
	SCHEDULE I - CONDENSED PARENT COMPANY
	FINANCIAL STATEMENTS - (Cont'd)
		December 31
		2013			2012
	(Millions of Dollars)
Assets
Current Assets
Cash and cash equivalents	$	0.3		$	0.9
Accounts and notes receivable from associated companies	37.4			32.9
Prepaid taxes and other	297.6			176.3
Total Current Assets	335.3			210.1
Property and Investments
Investment in subsidiary companies	4,761.80			4,662.30
Other	1.8			2.1
Total Property and Investments	4,763.60			4,664.40
Deferred Charges and Other Assets	143.2			331.4
Total Assets	$	5,242.10		$	5,205.90
Liabilities and Equity
Current Liabilities
Short-term debt	$	72		$	67
Notes payable due associated companies	113.8			140.6
Accrued taxes and other	11.8			34.7
Total Current Liabilities	197.6			242.3
Long-term debt	695			694.3
Other Long-term liabilities	116.5			134.2
Stockholder's equity	4,233.00			4,135.10
Total Liabilities and Equity	$	5,242.10		$	5,205.90
See accompanying notes to condensed parent company financial statements.
WISCONSIN ENERGY CORPORATION
NOTES TO FINANCIAL STATEMENTS
(Parent Company Only)
SCHEDULE I - CONDENSED PARENT COMPANY
FINANCIAL STATEMENTS - (Cont'd)
1.    For Parent Company only presentation, investment in subsidiaries are accounted for using the equity method. The condensed Parent Company financial statements and notes should be read in conjunction with the consolidated financial statements and notes of Wisconsin Energy Corporation appearing in this Annual Report on Form 10-K.
2.    Wisconsin Energy's ability as a holding company to pay common dividends primarily depends on the availability of funds received from the Parent Company's non-utility subsidiary, We Power, and its principal utility subsidiaries, Wisconsin Electric and Wisconsin Gas. During 2013, Wisconsin Electric and Wisconsin Gas collectively provided Wisconsin Energy with $373.0 million of dividends, and We Power provided $347.4 million of distributions.
Various financing arrangements and regulatory requirements impose certain restrictions on the ability of the Parent Company's subsidiaries to transfer funds to the Parent Company in the form of cash dividends, loans or advances. In addition, under Wisconsin law, Wisconsin Electric and Wisconsin Gas are prohibited from loaning funds, either directly or indirectly, to the Parent Company.
Wisconsin Energy does not believe that these restrictions will materially affect the Parent Company's operations or limit any dividend payments in the foreseeable future.
3.    As of December 31, 2013, the maturities of the Parent Company long-term debt outstanding were as follows:
	(Millions of Dollars)
2014	$	—
2015	—
2016	—
2017	—
2018	—
Thereafter	700
Total	$	700
Wisconsin Energy amortizes debt premiums, discounts and debt issuance costs over the lives of the debt and includes the costs in interest expense.
Wisconsin Energy entered into a new bank back-up credit facility in December 2012. The facility contains customary covenants, including certain limitations on Wisconsin Energy's ability to sell assets. The credit facility also contains customary events of default, including payment defaults, material inaccuracy of representations and warranties, covenant defaults, bankruptcy proceedings, certain judgments, ERISA defaults and change of control. In addition, pursuant to the terms of the credit facility, Wisconsin Energy must ensure that certain of its subsidiaries comply with several of the covenants contained therein. In addition, Wisconsin Energy is required to maintain, subject to certain exclusions, a minimum total funded debt to capitalization ratio of less than 70%.
As of December 31, 2013, Wisconsin Energy was in compliance with all covenants.
WECC is a subsidiary of Wisconsin Energy and has $50 million of long-term notes outstanding. In a Support Agreement between WECC and Wisconsin Energy, Wisconsin Energy agreed to make sufficient liquid asset contributions to WECC to permit WECC to service its debt obligations as they become due.
4.    Wisconsin Energy and certain of its subsidiaries enter into various guarantees to provide financial and performance assurance to third parties on behalf of affiliates. As of December 31, 2013, Wisconsin Energy had the following guarantees which are eliminated upon consolidation and not included in the Wisconsin Energy Notes to Consolidated Statements:
	Maximum						Liability
	Potential			Outstanding			Recorded
	Future			as of			as of
	Payments			Dec 31, 2013			Dec 31, 2013
	(Millions of Dollars)
Wisconsin Energy Guarantees
Utility	$	3.8		$	3.8		$	—
Non-Utility Energy	55.5			—			—
Other	0.3			—			—
Total	$	59.6		$	3.8		$	—
Letters of Credit	$	0.1		$	0.1		$	—
Utility guarantees support obligations of the utility segment under surety bonds, worker's compensation and agreements.
Wisconsin Energy's guarantees in support of its non-utility energy segment guaranty performance and payment obligations of We Power. The guarantees which support We Power are for obligations under purchase, construction and lease agreements with the utility segment and third parties.
Wisconsin Energy has a guarantee that supports an environmental indemnification obligation, which is unlimited, associated with the Minergy Neenah plant and indemnifications related to the post-closing obligations under the Minergy Neenah sale agreement which was entered into in September 2006. In the event the guarantee fails to perform, Wisconsin Energy would be responsible for the obligations.
5.    The carrying amount and estimated fair value of certain of our recorded financial instruments as of December 31 are as follows:
		2013						2012
		Carrying			Fair			Carrying		Fair
Financial Instruments		Amount			Value			Amount		Value
		(Millions of Dollars)
Long-term debt including current portion		$	700		$	749.4		$	700	$	805.9
The carrying value of net accounts receivable, accounts payable and short-term borrowings approximates fair value due to the short-term nature of these instruments. The fair value of our long-term debt, including the current portion of long-term debt, and unamortized discount on debt, is estimated based upon quoted market value for the same or similar issues or upon the quoted market prices of U.S. Treasury issues having a similar term to maturity, adjusted for the Parent Company's bond rating and the present value of future cash flows.
6.    During the year ended December 31, 2013, Wisconsin Energy paid $44.4 million in interest, net of amounts capitalized, and received $86.1 million in refunds from income taxes. During the year ended December 31, 2012, Wisconsin Energy paid $45.2 million in interest, net of amounts capitalized, and received $128.2 million in refunds from income taxes. During the year ended December 31, 2011, Wisconsin Energy paid $57.7 million in interest, net of amounts capitalized, and received $114.6 million in refunds from income taxes.
Subsequent Event: On January 16, 2014, Wisconsin Electric's board of directors declared a special dividend of $50.0 million which was paid to Wisconsin Energy on January 30, 2014.

Schedule_II_Valuation_and_Qual

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2013
Valuation and Qualifying Accounts [Abstract]	'
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	'
	SCHEDULE II	VALUATION AND QUALIFYING ACCOUNTS
	Allowance for Doubtful Accounts		Balance at Beginning of the Period		Expense		Deferral			Net Write-offs			Balance at End of the Period
			(Millions of Dollars)
	December 31, 2013		$	58	$	49.4	$	0.4		$	(46.8	)	$	61
	December 31, 2012		$	61.7	$	47.7	$	(4.0	)	$	(47.4	)	$	58
	December 31, 2011		$	58.1	$	85.8	$	(35.9	)	$	(46.3	)	$	61.7

Preferred_Stock_Notes

Preferred Stock (Notes)	12 Months Ended
	Dec. 31, 2013
Preferred Stock [Abstract]	'
Preferred Stock [Text Block]	'
	PREFERRED STOCK
	The following table shows preferred stock authorized and outstanding at December 31, 2013 and 2012:
		Shares Authorized	Shares Outstanding	Redemption Price Per Share		Total
						(In Millions)
	Wisconsin Energy
	$.01 par value Preferred Stock	15,000,000	—	—		$	—
	Wisconsin Electric
	$100 par value, Six Per Cent. Preferred Stock	45,000	44,498	—		$	4.4
	$100 par value, Serial Preferred Stock	2,286,500
	3.60% Series		260,000	$	101	26
	$25 par value, Serial Preferred Stock	5,000,000	—	—		—
	Total preferred stock of subsidiary					$	30.4

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Summary of Significant Accounting Policies (Policies) [Abstract]	'
Consolidation	'
	General:   Our consolidated financial statements include the accounts of Wisconsin Energy Corporation (Wisconsin Energy, the Company, our, we or us), a diversified holding company, as well as our subsidiaries in the following reportable segments:
	•	Utility Energy Segment -- Consisting of Wisconsin Electric and Wisconsin Gas, engaged primarily in the generation of electricity and the distribution of electricity and natural gas; and
	•	Non-Utility Energy Segment -- Consisting primarily of We Power, engaged principally in the ownership of electric power generating facilities for long-term lease to Wisconsin Electric.
	Our Corporate and Other segment includes Wispark, which develops and invests in real estate. We have also eliminated all intercompany transactions from the consolidated financial statements.
Basis of Accounting	'
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and disclosure of contingent assets and liabilities at the date of financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Reclassifications	'
	Reclassifications and Adjustments:  As of December 31, 2013, we have presented the tax effect of net operating loss carryforwards within current deferred tax assets, net on the consolidated balance sheets. As of December 31, 2012, $59.0 million representing the tax effect of net operating loss carryforwards were included in income taxes receivable, which is a line item that has now been condensed within other current assets on the consolidated balance sheets. This $59.0 million amount has been adjusted in the consolidated balance sheets as of December 31, 2012 to conform to the December 31, 2013 presentation, and conforming changes have been made in the consolidated statements of cash flows and in the notes to the consolidated financial statements. For additional information related to our deferred tax assets, see Note G.
	In addition, we have adjusted the presentation of regulatory assets and liabilities to present amounts as noncurrent assets and liabilities on the consolidated balance sheets. Prior period amounts recorded within other current assets and liabilities have been reclassified to conform to the current presentation. For additional information related to regulatory assets and liabilities, see Note C.
Revenues	'
	Revenues:   We recognize energy revenues on the accrual basis and include estimated amounts for services rendered but not billed.
	Our retail electric rates in Wisconsin are established by the PSCW and include base amounts for fuel and purchased power costs. The electric fuel rules in Wisconsin allow us to defer, for subsequent rate recovery or refund, any under-collection or over-collection of fuel costs that are outside of the symmetrical fuel cost tolerance, which the PSCW set at plus or minus 2% of the approved fuel cost plan. The deferred under-collected amounts are subject to an excess revenues test.
	Our retail gas rates include monthly adjustments which permit the recovery or refund of actual purchased gas costs. We defer any difference between actual gas costs incurred (adjusted for a sharing mechanism) and costs recovered through rates as a current asset or liability. The deferred balance is returned to or recovered from customers at intervals throughout the year.
	We recognize We Power revenues (consisting of the lease payments included in rates and the amortization of the deferred revenue) on a levelized basis over the term of the lease.
Accounting For MISO Energy Transactions	'
	Accounting for MISO Energy Transactions:   The MISO Energy Markets operate under both day-ahead and real-time markets. We record energy transactions in the MISO Energy Markets on a net basis for each hour.
Property and Depreciation	'
	Property and Depreciation:   We record property, plant and equipment at cost. Cost includes material, labor, overheads and capitalized interest. Utility property also includes AFUDC - Equity. Additions to and significant replacements of property are charged to property, plant and equipment at cost; minor items are charged to maintenance expense. The cost of depreciable utility property less salvage value is charged to accumulated depreciation when property is retired.
	We recorded the following property in service by segment as of December 31:
	Property In Service		2013		2012
			(Millions of Dollars)
	Utility Energy		$	11,779.80	$	11,080.90
	Non-Utility Energy		3,091.30		3,068.50
	Other		95.2		89.4
	Total		$	14,966.30	$	14,238.80
	Our utility depreciation rates are certified by the PSCW and MPSC and include estimates for salvage value and removal costs. Depreciation as a percent of average depreciable utility plant was 2.9% in 2013 and 2012, and 2.8% in 2011.
	We depreciate our We Power assets over the estimated useful life of the various property components. The components have useful lives of between 10 to 45 years for PWGS 1 and PWGS 2, and 10 to 55 years for OC 1 and OC 2.
	Our regulated utilities collect in their rates amounts representing future removal costs for many assets that do not have an associated Asset Retirement Obligation (ARO). We record a regulatory liability on our balance sheet for the estimated amounts we have collected in rates for future removal costs less amounts we have spent in removal activities. This regulatory liability was $724.5 million as of December 31, 2013 and $725.0 million as of December 31, 2012.
	We recorded the following Construction Work in Progress (CWIP) by segment as of December 31:
	CWIP		2013		2012
			(Millions of Dollars)
	Utility Energy		$	132.7	$	298.2
	Non-Utility Energy		16.5		13.3
	Other		0.4		4.4
	Total		$	149.6	$	315.9
Allowance For Funds Used During Construction - Regulated	'
	Allowance For Funds Used During Construction - Regulated:   AFUDC is included in utility plant accounts and represents the cost of borrowed funds (AFUDC - Debt) used during plant construction, and a return on stockholders' capital (AFUDC - Equity) used for construction purposes. AFUDC - Debt is recorded as a reduction of interest expense, and AFUDC - Equity is recorded in Other Income and Deductions, net.
Capitalized Interest And Carrying Costs Non Regulated Energy Policy [Text Block]	'
	Capitalized Interest and Carrying Costs - Non-Regulated Energy:   As part of the construction of the PTF electric generating units, we capitalized interest during construction. As allowed under the lease agreements, we were able to collect the carrying costs during the construction of the PTF generating units from our utility customers. The carrying costs that we collected during construction have been recorded as deferred revenue on our balance sheet and we are amortizing the deferred carrying costs to revenue over the individual lease terms.
Earning per Common Share	'
	Earnings per Common Share:   We compute basic earnings per common share by dividing our net income attributed to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per common share is computed by dividing net income attributed to common shareholders by the weighted average number of common shares outstanding during the period, adjusted for the exercise and/or conversion of all potentially dilutive securities. Such dilutive securities include in-the-money stock options. All stock options outstanding during 2013, 2012 and 2011 were included in the computation of diluted earnings per share. Anti-dilutive shares are excluded from the calculation.
Materials, Supplies and Inventories	'
	Materials, Supplies and Inventories:   Our inventory as of December 31 consists of:
	Materials, Supplies and Inventories		2013		2012
			(Millions of Dollars)
	Fossil Fuel		$	117.7	$	165.5
	Materials and Supplies		133.9		121.9
	Natural Gas in Storage		77.8		73.3
	Total		$	329.4	$	360.7
	Substantially all fossil fuel, materials and supplies, and natural gas in storage inventories are recorded using the weighted-average cost method of accounting.
Regulatory Accounting	'
	Regulatory Accounting:   The economic effects of regulation can result in regulated companies recording costs that have been or are expected to be allowed in the rate-making process in a period different from the period in which the costs would be charged to expense by an unregulated enterprise. When this occurs, costs are deferred as regulatory assets on the balance sheet and expensed in the periods when they are reflected in rates. We defer regulatory assets pursuant to specific or generic orders issued by our regulators. Additionally, regulators can impose regulatory liabilities upon a regulated company for amounts previously collected from customers and for amounts that are expected to be refunded to customers. In general, regulatory assets are recovered in a period between one to eight years. For further information, see Note C.
Asset Retirement Obligations	'
	Asset Retirement Obligations:   We record a liability for a legal ARO in the period in which it is incurred. When a new legal obligation is recorded, we capitalize the costs of the liability by increasing the carrying amount of the related long-lived asset. We accrete the liability to its present value each period and depreciate the capitalized cost over the useful life of the related asset. At the end of the asset's useful life, we settle the obligation for its recorded amount or incur a gain or loss. As it relates to our regulated operations, we apply regulatory accounting guidance and recognize regulatory assets or liabilities for the timing differences between when we recover legal AROs in rates and when we would recognize these costs. For further information, see Note E.
Derivative Financial Instruments	'
	Derivative Financial Instruments:   We have derivative physical and financial instruments which we report at fair value. For further information, see Note L.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents:   Cash and cash equivalents include marketable debt securities acquired three months or less from maturity.
Margin Accounts	'
	Margin Accounts:   Cash deposited in brokerage accounts for margin requirements is recorded in Other Current Assets on our Consolidated Balance Sheets.
Goodwill	'
	Goodwill:   Goodwill reflects the cost of an acquisition in excess of the fair values assigned to identifiable net assets acquired. As of December 31, 2013 and 2012, we had $441.9 million of goodwill recorded at the utility energy segment, which related to our acquisition of Wisconsin Gas in 2000.
	Goodwill is not subject to amortization. However, it is subject to fair value-based rules for measuring impairment, and resulting write-downs, if any, are to be reflected in operating expense. Fair value is assessed by considering future discounted cash flows, a comparison of fair value based on public company trading multiples, and merger and acquisition transaction multiples for similar companies. This evaluation utilizes the information available under the circumstances, including reasonable and supportable assumptions and projections. We perform our annual impairment test as of August 31. There was no impairment to the recorded goodwill balance as of our annual 2013 impairment test date.
Impairment or Disposal of Long Lived Assets	'
	Impairment or Disposal of Long Lived Assets:   We carry property, equipment and goodwill related to businesses held for sale at the lower of cost or estimated fair value less cost to sell. As of December 31, 2013, we had no assets classified as Held for Sale. Long-lived assets are tested for recoverability whenever events or changes in circumstances indicate that their carrying value may not be recoverable from the use and eventual disposition of the asset based on the remaining useful life. An impairment loss is recognized when the carrying amount of an asset is not recoverable and exceeds the fair value of the asset. The carrying amount of an asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. An impairment loss is measured as the excess of the carrying amount of the asset in comparison to the fair value of the asset.
Investments	'
	Investments:   We account for investments in other affiliated companies in which we do not maintain control using the equity method of accounting. We had a total ownership interest of approximately 26.2% in ATC as of December 31, 2013 and 2012. We are represented by one out of ten ATC board members, each of whom has one vote. Due to the voting requirements, no individual member has more than 10% of the voting control. For further information regarding such investments, see Note P.
Income Taxes	'
	Income Taxes:   We follow the liability method in accounting for income taxes. Accounting guidance for income taxes requires the recording of deferred assets and liabilities to recognize the expected future tax consequences of events that have been reflected in our financial statements or tax returns and the adjustment of deferred tax balances to reflect tax rate changes. We are required to assess the likelihood that our deferred tax assets would expire before being realized. If we conclude that certain deferred tax assets are likely to expire before being realized, a valuation allowance would be established against those assets. GAAP requires that, if we conclude in a future period that it is more likely than not that some or all of the deferred tax assets would be realized before expiration, we reverse the related valuation allowance in that period. Any change to the allowance, as a result of a change in judgment about the realization of deferred tax assets, is reported in income tax expense.
	Investment tax credits associated with regulated operations are deferred and amortized over the life of the assets. We file a consolidated Federal income tax return. Accordingly, we allocate Federal current tax expense benefits and credits to our subsidiaries based on their separate tax computations. For further information, see Note G.
	We recognize interest and penalties accrued related to unrecognized tax benefits in Income Taxes in our Consolidated Income Statements, as well as Regulatory Assets or Regulatory Liabilities in our Consolidated Balance Sheets.
	We collect sales and use taxes from our customers and remit these taxes to governmental authorities. These taxes are recorded in our Consolidated Income Statements on a net basis.
Stock Options	'
	Stock Options:   We estimate the fair value of stock options using the binomial pricing model. We report unearned stock-based compensation associated with non-vested restricted stock and performance share awards activity within Other Paid in Capital in our Consolidated Statements of Common Equity. We report excess tax benefits as a financing cash inflow. Historically, all stock options have been granted with an exercise price equal to the fair market value of the common stock on the date of grant and expire no later than 10 years from grant date. For a discussion of the impacts to our Consolidated Financial Statements, see Note H.
Treasury Grant Accounting Policy [Policy Text Block]	'
	Treasury Grant:   In December 2013, we filed an application with the United States Treasury for a Section 1603 renewable energy grant related to the construction of our biomass facility in Rothschild, Wisconsin. The PSCW anticipated the recognition of this grant as income when it set rates for the two years beginning January 1, 2013. We provided bill credits to our customers in 2013, and this will continue into 2014. As of December 31, 2013, $48.0 million was recognized as income, which reflects the amount that was returned to customers in the form of bill credits during the year. We recorded an $82.6 million receivable, and deferred the balance that we expect to benefit our customers in the future. The accounting reflects the regulatory treatment of the grant.
	The PSCW approved escrow accounting treatment for the Treasury Grant. Under escrow accounting, we true-up any differences between the actual grant proceeds received and the grant proceeds passed on to customers in the form of bill credits.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of Significant Accounting Policies (Tables) [Abstract]	'
Other Income and Deductions, Net	'
	Other Income and Deductions, Net:   We recorded the following items in Other Income and Deductions, net for the years ended December 31:
	Other Income and Deductions, net		2013			2012				2011
			(Millions of Dollars)
	AFUDC - Equity		$	18.3		$	35.3			$	59.4
	Other, net		0.5			(0.5		)		3.3
	Total Other Income and Deductions, net		$	18.8		$	34.8			$	62.7
Property In Service By Segment	'
	Property and Depreciation:   We record property, plant and equipment at cost. Cost includes material, labor, overheads and capitalized interest. Utility property also includes AFUDC - Equity. Additions to and significant replacements of property are charged to property, plant and equipment at cost; minor items are charged to maintenance expense. The cost of depreciable utility property less salvage value is charged to accumulated depreciation when property is retired.
	We recorded the following property in service by segment as of December 31:
	Property In Service		2013			2012
			(Millions of Dollars)
	Utility Energy		$	11,779.80		$	11,080.90
	Non-Utility Energy		3,091.30			3,068.50
	Other		95.2			89.4
	Total		$	14,966.30		$	14,238.80
	Our utility depreciation rates are certified by the PSCW and MPSC and include estimates for salvage value and removal costs. Depreciation as a percent of average depreciable utility plant was 2.9% in 2013 and 2012, and 2.8% in 2011.
	We depreciate our We Power assets over the estimated useful life of the various property components. The components have useful lives of between 10 to 45 years for PWGS 1 and PWGS 2, and 10 to 55 years for OC 1 and OC 2.
	Our regulated utilities collect in their rates amounts representing future removal costs for many assets that do not have an associated Asset Retirement Obligation (ARO). We record a regulatory liability on our balance sheet for the estimated amounts we have collected in rates for future removal costs less amounts we have spent in removal activities. This regulatory liability was $724.5 million as of December 31, 2013 and $725.0 million as of December 31, 2012.
	We recorded the following Construction Work in Progress (CWIP) by segment as of December 31:
	CWIP		2013			2012
			(Millions of Dollars)
	Utility Energy		$	132.7		$	298.2
	Non-Utility Energy		16.5			13.3
	Other		0.4			4.4
	Total		$	149.6		$	315.9
Construction Work in Progress (CWIP) by segment	'
	We recorded the following Construction Work in Progress (CWIP) by segment as of December 31:
	CWIP		2013			2012
			(Millions of Dollars)
	Utility Energy		$	132.7		$	298.2
	Non-Utility Energy		16.5			13.3
	Other		0.4			4.4
	Total		$	149.6		$	315.9
Allowance For Funds Used During Construction	'
	Our regulated utility segment recorded the following AFUDC for the years ended December 31:
		2013			2012				2011
		(Millions of Dollars)
	AFUDC - Debt	$	7.7		$	14.7			$	24.7
	AFUDC - Equity	$	18.3		$	35.3			$	59.4
Inventories	'
	Materials, Supplies and Inventories:   Our inventory as of December 31 consists of:
	Materials, Supplies and Inventories		2013			2012
			(Millions of Dollars)
	Fossil Fuel		$	117.7		$	165.5
	Materials and Supplies		133.9			121.9
	Natural Gas in Storage		77.8			73.3
	Total		$	329.4		$	360.7
	Substantially all fossil fuel, materials and supplies, and natural gas in storage inventories are recorded using the weighted-average cost method of accounting.
Fair value of stock options	'
	The fair value of our stock options was calculated using a binomial option-pricing model using the following weighted-average assumptions:
		2013		2012	2011
	Risk-free interest rate	0.1% - 1.9%		0.1% - 2.0%	0.2% - 3.4%
	Dividend yield	3.70%		3.90%	3.90%
	Expected volatility	18.00%		19.00%	19.00%
	Expected life (years)	5.9		5.9	5.5
	Expected forfeiture rate	2.00%		2.00%	2.00%
	Weighted-average fair value
	of our stock options granted	$3.45		$3.34	$3.17
Property In Services By Segment [Text Block]	'
	We recorded the following property in service by segment as of December 31:
	Property In Service		2013			2012
			(Millions of Dollars)
	Utility Energy		$	11,779.80		$	11,080.90
	Non-Utility Energy		3,091.30			3,068.50
	Other		95.2			89.4
	Total		$	14,966.30		$	14,238.80

Regulatory_Assets_and_Liabilit1

Regulatory Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Regulatory Assets and Liabilities (Tables) [Abstract]	'
Regulatory assets and liabilities	'
	Our regulatory assets and liabilities as of December 31 consist of:
		2013		2012
		(Millions of Dollars)
	Regulatory Assets
	Deferred unrecognized pension costs	$	537.6	$	731.5
	Deferred income tax related	169.5		176.5
	Escrowed electric transmission costs	126.8		114.1
	Escrowed conservation	66.9		73.5
	Deferred plant related -- capital lease	56.5		66.6
	Deferred environmental costs	47		47.4
	Other, net	104.2		170.7
	Total regulatory assets	$	1,108.50	$	1,380.30
	Regulatory Liabilities
	Deferred cost of removal obligations	$	724.5	$	725
	Escrowed bad debt costs	64.6		81.1
	Other, net	90		62.2
	Total regulatory liabilities	$	879.1	$	868.3

Recovered_Sheet1

Asset Sales, Divestitures And Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2013
Asset Sales, Divestitures And Discontinued Operations (Tables) [Abstract]	'
Net impacts of the discontinued operations on earnings	'
	The following table summarizes the net impacts of the discontinued operations on our earnings for the years ended December 31:
		2013		2012		2011
		(Millions of Dollars)
	Income from Continuing Operations	$	577.4	$	546.3	$	512.8
	Income from Discontinued other operations, net of tax (a)	—		—		13.4
	Net Income	$	577.4	$	546.3	$	526.2
	(a)	Primarily relates to the favorable resolution of uncertain state and federal tax positions associated with our previously discontinued manufacturing business.

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2013
Asset Retirement Obligations (Tables) [Abstract]	'
Change in Asset Retirement Obligations	'
	The following table presents the change in our AROs during 2013 and 2012:
		2013			2012
		(Millions of Dollars)
	Balance as of January 1	$	44.3		$	55.5
	Liabilities Settled	(4.4		)	(14.0		)
	Accretion	2.4			2.8
	Balance as of December 31	$	42.3		$	44.3

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Taxes (Tables) [Abstract]	'
Summary of income tax expense	'
	The following table is a summary of income tax expense for each of the years ended December 31:
	Income Taxes		2013				2012				2011
			(Millions of Dollars)
	Current tax expense (benefit)		$	25.2			$	13.1			$	(166.7	)
	Deferred income taxes, net		313.8				294.4				434.8
	Investment tax credit, net		(1.1		)		(1.2		)		(4.2		)
	Total Income Tax Expense		$	337.9			$	306.3			$	263.9
The provision for income taxes for each of the years ended December 31 differs from the amount of income tax determined by applying the applicable U.S. statutory federal income tax rate to income before income taxes as a result of the following:	'
	The provision for income taxes for each of the years ended December 31 differs from the amount of income tax determined by applying the applicable U.S. statutory federal income tax rate to income before income taxes as a result of the following:
			2013							2012						2011
							Effective							Effective					Effective
	Income Tax Expense		Amount				Tax Rate			Amount				Tax Rate		Amount			Tax Rate
			(Millions of Dollars)
	Expected tax at statutory federal tax rates		$	320.3			35	%		$	298.4			35	%	$	271.8		35	%
	State income taxes net of federal tax benefit		49				5.3	%		43.3				5.1	%	40.1			5.2	%
	Production tax credits		(16.7		)		(1.8	)%		(15.9		)		(1.9	)%	(8.7		)	(1.1	)%
	Treasury Grant		(7.4		)		(0.8	)%		—				—	%	—			—	%
	AFUDC - Equity		(6.4		)		(0.7	)%		(12.3		)		(1.4	)%	(20.8		)	(2.7	)%
	Investment tax credit restored		(1.1		)		(0.1	)%		(1.2		)		(0.1	)%	(4.2		)	(0.5	)%
	Domestic production activities deduction		—				—	%		(12.6		)		(1.5	)%	(12.6		)	(1.6	)%
	Other, net		0.2				—	%		6.6				0.7	%	(1.7		)	(0.3	)%
	Total Income Tax Expense		$	337.9			36.9	%		$	306.3			35.9	%	$	263.9		34	%
Components of deferred income taxes classified as net current assets and net long-term liabilities	'
	The components of deferred income taxes classified as net current assets and net long-term liabilities as of December 31 are as follows:
	Deferred Tax Assets		2013				2012
			(Millions of Dollars)
	Current
	Future federal tax benefits		$	309.7			$	59
	Employee benefits and compensation		13.8				14.9
	Other		56				81.1
	Total Current Deferred Tax Assets		379.5				155
	Non-current
	Deferred revenues		237				250
	Employee benefits and compensation		95.6				97
	Future federal tax benefits		32.5				334.7
	Property-related		28.2				28.3
	Construction advances		18.3				22.2
	Other		62.9				16.3
	Total Non-Current Deferred Tax Assets		474.5				748.5
	Total Deferred Tax Assets		$	854			$	903.5
	Deferred Tax Liabilities		2013				2012
			(Millions of Dollars)
	Current
	Prepaid items		$	69.5			$	49.7
	Total Current Deferred Tax Liabilities		69.5				49.7
	Non-current
	Property-related		2,574.40				2,339.40
	Employee benefits and compensation		238.5				244.3
	Investment in transmission affiliate		169.9				144.9
	Deferred transmission costs		50.8				45.7
	Other		74.9				91.2
	Total Non-current Deferred Tax Liabilities		3,108.50				2,865.50
	Total Deferred Tax Liabilities		$	3,178.00			$	2,915.20
	Consolidated Balance Sheet Presentation		2013				2012
	Current Deferred Tax Asset		$	310			$	105.3
	Non-Current Deferred Tax Liability		$	2,634.00			$	2,117.00
Reconciliation of the beginning and ending amount of unrecognized tax benefits	'
	We previously adopted accounting guidance related to uncertainty in income taxes. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
		2013				2012
		(Millions of Dollars)
	Balance as of January 1	$	11.3			$	11.1
	Additions for tax positions of prior years	—				10.8
	Reductions for tax positions of prior years	(2.9		)		(10.6		)
	Balance as of December 31	$	8.4			$	11.3

Common_Equity_Tables

Common Equity (Tables)	12 Months Ended
	Dec. 31, 2013
Common Equity (Tables) [Abstract]	'
Recorded pre-tax share-based compensation expense and related tax benefit for share-based awards made to employees and directors	'
	The following table summarizes recorded pre-tax share-based compensation expense and the related tax benefit for share-based awards made to our employees and directors as of December 31:
		2013			2012		2011
		(Millions of Dollars)
	Performance units	$	12.7		$	16.3	$	24.1
	Stock options	3.9			2.7		2.6
	Restricted stock	2.4			3		1.8
	Share-based compensation expense	$	19		$	22	$	28.5
	Related Tax Benefit	$	7.6		$	8.8	$	11.4
Stock option activity	'
	The following is a summary of our stock option activity during 2013:
	Stock Options		Number of Options		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (Millions)
	Outstanding as of January 1, 2013		8,919,669		$	23.86
	Granted		1,418,560		$	37.46
	Exercised		(2,238,489	)	$	21.67
	Forfeited		(10,030	)	$	35.37
	Outstanding as of December 31, 2013		8,089,710		$	26.84	5.4		$	117.3
	Exercisable as of December 31, 2013		5,708,920		$	23.16	4.1		$	103.8
Stock options outstanding	'
	The following table summarizes information about stock options outstanding as of December 31, 2013:
			Options Outstanding						Options Exercisable
					Weighted-Average						Weighted-Average
	Range of Exercise Prices		Number of Options		Exercise Price		Remaining Contractual Life (Years)		Number of Options		Exercise Price		Remaining Contractual Life (Years)
	$16.72  to  $21.11		2,128,370		$	20.34	3.9		2,128,370		$	20.34	3.9
	$23.88  to  $29.35		3,689,900		$	24.65	4.2		3,382,630		$	24.23	4
	$34.88  to  $37.46		2,271,440		$	36.48	8.6		197,920		$	35.19	8.1
			8,089,710		$	26.84	5.4		5,708,920		$	23.16	4.1
Non-vested options	'
	The following table summarizes information about our non-vested options during 2013:
	Non-Vested Stock Options		Number of Options		Weighted- Average Fair Value
	Non-Vested as of January 1, 2013		1,702,275		$	3.31
	Granted		1,418,560		$	3.45
	Vested		(730,015	)	$	3.34
	Forfeited		(10,030	)	$	3.37
	Non-Vested as of December 31, 2013		2,380,790		$	3.38
Restricted stock activity	'
	Restricted Shares:   The Compensation Committee has also approved restricted stock grants to certain key employees and directors. The following restricted stock activity occurred during 2013:
	Restricted Shares		Number of Shares		Weighted-Average Market Price
	Outstanding as of January 1, 2013		188,222
	Granted		74,290		$	37.65
	Released		(97,973	)	$	26.65
	Forfeited		(13,841	)	$	33.35
	Outstanding as of December 31, 2013		150,698

LongTerm_Debt_and_Capital_Leas1

Long-Term Debt and Capital Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2013
Long-Term Debt and Capital Lease Obligations (Tables) [Abstract]	'
Long-term debt outstanding maturities and sinking fund requirements	'
	Debentures and Notes:   As of December 31, 2013, the maturities and sinking fund requirements of our long-term debt outstanding (excluding obligations under capital leases) were as follows:
		(Millions of Dollars)
	2014	$	322.4
	2015	399.5
	2016	27.4
	2017	29.5
	2018	281.1
	Thereafter	3,566.80
	Total	$	4,626.70
Summary of capitalized leased facilities	'
	The following is a summary of our capitalized leased facilities as of December 31:
	Capital Lease Assets		2013			2012
			(Millions of Dollars)
	Leased Facilities
	Long-term power purchase commitment		$	140.3		$	140.3
	Accumulated amortization		(92.5		)	(86.8		)
	Total Leased Facilities		$	47.8		$	53.5
Future minimum lease payments under capital lease and present value of net minimum lease payments	'
	Future minimum lease payments under our capital lease and the present value of our net minimum lease payments as of December 31, 2013 are as follows:
		(Millions of Dollars)
	2014	$	41.9
	2015	43.5
	2016	45.1
	2017	13.9
	2018	14.7
	Thereafter	56.8
	Total Minimum Lease Payments	215.9
	Less:  Estimated Executory Costs	(61.7		)
	Net Minimum Lease Payments	154.2
	Less:  Interest	(49.9		)
	Present Value of Net
	Minimum Lease Payments	104.3
	Less:  Due Currently	(19.8		)
		$	84.5

ShortTerm_Debt_Tables

Short-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Short-Term Debt (Tables) [Abstract]	'
Short-term notes payable balances and their corresponding weighted-average interest rates	'
	Short-term notes payable balances and their corresponding weighted-average interest rates as of December 31 consist of:
			2013					2012
						Interest				Interest
	Short-Term Debt		Balance			Rate		Balance		Rate
			(Millions of Dollars, except for percentages)
	Commercial paper		$	537.4		0.2	%	$	394.6	0.3	%
Commercial paper	'
	The following information relates to commercial paper for the years ended December 31:
		2013			2012
		(Millions of Dollars, except for percentages)
	Maximum Short-Term Debt Outstanding	$	594.5		$	669.9
	Average Short-Term Debt Outstanding	$	359.1		$	481.6
	Weighted-Average Interest Rate	0.25		%	0.28		%

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments (Tables) [Abstract]	'
Derivative instruments in balance sheet	'
	We record our current derivative assets on the balance sheet in other current assets and the current portion of the liabilities in other current liabilities. The long-term portion of our derivative assets of $0.4 million is recorded in other deferred charges and other assets, and we had no long-term portion of derivative liabilities. Our Consolidated Balance Sheets as of December 31, 2013 and 2012 include:
		December 31, 2013							December 31, 2012
		Derivative				Derivative			Derivative			Derivative
		Asset				Liability			Asset			Liability
		(Millions of Dollars)
	Natural Gas	$	5.6			$	0.1		$	3		$	1.9
	Fuel Oil	0.6				—			0.4			—
	FTRs	3.5				—			4.7			—
	Coal	2.1				0.2			11.1			—
	Total	$	11.8			$	0.3		$	19.2		$	1.9
Derivative instruments' estimated notional volumes and gain (losses)	'
	Our Consolidated Income Statements include gains (losses) on derivative instruments used in our risk management strategies under fuel and purchased power for those commodities supporting our electric operations and under cost of gas sold for the natural gas sold to our customers. Our estimated notional volumes and gains (losses) for the years ended December 31 were as follows:
		2013						2012
		Volume		Gains (Losses)				Volume	Gains (Losses)
				(Millions of Dollars)					(Millions of Dollars)
	Natural Gas	48.6 million Dth		$	(8.5	)		77.2 million Dth	$	(36.3	)
	Fuel Oil	8.6 million gallons		0.5				7.0 million gallons	1.8
	FTRs	25.3 million MWh		14.9				25.1 million MWh	6.1
	Total			$	6.9				$	(28.4	)
Offsetting Assets and Liabilities [Table Text Block]	'
		2013							2012
		Derivative				Derivative			Derivative			Derivative
		Asset				Liability			Asset			Liability
		(Millions of Dollars)
	Gross Amount Recognized on the Balance Sheet	$	11.8			$	0.3		$	19.2		$	1.9
	Gross Amount Not Offset on Balance Sheet (a)	—				—			(0.5		)	(1.8		)
	Net Amount	$	11.8			$	0.3		$	18.7		$	0.1
	(a)	Gross Amount Not Offset on Balance Sheet includes cash collateral posted of zero and $1.3 million as of December 31, 2013 and 2012, respectively.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Measurements (Tables) [Abstract]	'
Financial assets and liabilities by level within the fair value hierarchy	'
	The following tables summarize our financial assets and liabilities by level within the fair value hierarchy:
	Recurring Fair Value Measures		As of December 31, 2013
			Level 1			Level 2		Level 3		Total
			(Millions of Dollars)
	Assets:
	Derivatives		$	5.7		$	2.6	$	3.5	11.8
	Total		$	5.7		$	2.6	$	3.5	$	11.8
	Liabilities:
	Derivatives		$	—		$	0.3	$	—	$	0.3
	Total		$	—		$	0.3	$	—	$	0.3
	Recurring Fair Value Measures		As of December 31, 2012
			Level 1			Level 2		Level 3		Total
			(Millions of Dollars)
	Assets:
	Restricted Cash		$	2.7		$	—	$	—	$	2.7
	Derivatives		2.2			12.3		4.7		19.2
	Total		$	4.9		$	12.3	$	4.7	$	21.9
	Liabilities:
	Derivatives		$	1.9		$	—	$	—	$	1.9
	Total		$	1.9		$	—	$	—	$	1.9
Fair value of derivatives classified as Level 3 in the fair value hierarchy	'
	The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy:
		2013			2012
		(Millions of Dollars)
	Balance as of January 1	$	4.7		$	5.7
	Realized and unrealized gains (losses)	—			—
	Purchases	10.6			11
	Issuances	—			—
	Settlements	(11.8		)	(12.0		)
	Transfers in and/or out of Level 3	—			—
	Balance as of December 31	$	3.5		$	4.7
	Change in unrealized gains (losses) relating to instruments still held as of December 31	$	—		$	—
Carrying amount and estimated fair value of certain financial instruments	'
	The carrying amount and estimated fair value of certain of our recorded financial instruments as of December 31 are as follows:
			2013					2012
			Carrying			Fair		Carrying		Fair
	Financial Instruments		Amount			Value		Amount		Value
			(Millions of Dollars)
	Preferred stock, no redemption required		$	30.4		$	26	$	30.4	$	26
	Long-term debt including current portion		$	4,626.70		$	4,911.80	$	4,772.90	$	5,447.30

Benefits_Tables

Benefits (Tables)	12 Months Ended
	Dec. 31, 2013
Benefits (Tables) [Abstract]	'
Details about pension and OPEB plans	'
	The following table presents details about our pension and OPEB plans:
		Pension							OPEB
		2013				2012			2013			2012
		(Millions of Dollars)
	Change in Benefit Obligation
	Benefit Obligation at January 1	$	1,508.50			$	1,330.60		$	381.2		$	389.7
	Service cost	14.6				21.7			10			10.3
	Interest cost	60.4				65.5			15.6			20.3
	Participants' contributions	—				—			8.9			9.6
	Plan amendments	(1.0		)		—			—			0.5
	Actuarial loss (gain)	(81.9		)		166.5			(27.7		)	(23.8		)
	Other accrued benefits	—				31.4			—			—
	Gross benefits paid	(90.4		)		(107.2		)	(26.3		)	(26.3		)
	Federal subsidy on benefits paid	N/A				N/A			1			0.9
	Benefit Obligation at December 31	$	1,410.20			$	1,508.50		$	362.7		$	381.2
	Change in Plan Assets
	Fair Value at January 1	$	1,385.40			$	1,262.50		$	285.4		$	255.4
	Actual earnings on plan assets	147.3				127.4			45.5			29
	Employer contributions	8.7				102.7			14.1			17.7
	Participants' contributions	—				—			8.9			9.6
	Gross benefits paid	(90.4		)		(107.2		)	(26.3		)	(26.3		)
	Fair Value at December 31	$	1,451.00			$	1,385.40		$	327.6		$	285.4
	Net asset (liability)	$	40.8			$	(123.1	)	$	(35.1	)	$	(95.8	)
Amounts recognized in Consolidated Balance Sheets	'
	Amounts recognized in our Consolidated Balance Sheets as of December 31 related to the funded status of the benefit plans consisted of:
		Pension							OPEB
		2013				2012			2013			2012
		(Millions of Dollars)
	Other long-term assets	$	138.7			$	—		$	40.2		$	25.1
	Other long-term liabilities	$	97.9			$	123.1		$	75.3		$	120.9
Amounts not yet been recognized in net periodic benefit cost	'
	The following table shows the amounts that have not yet been recognized in our net periodic benefit cost as of December 31 and are recorded as a regulatory asset on our balance sheet:
		Pension							OPEB
		2013				2012			2013			2012
		(Millions of Dollars)
	Net actuarial loss	$	528.8			$	719.2		$	9.8		$	65.3
	Prior service costs (credits)	8.8				12.2			(1.7		)	(3.7		)
	Total - Regulatory Assets	$	537.6			$	731.4		$	8.1		$	61.6
Components of net periodic pension and OPEB costs	'
	The components of net periodic pension and OPEB costs for the years ended December 31 are as follows:
		Pension										OPEB
		2013				2012			2011			2013			2012			2011
		(Millions of Dollars)
	Net Periodic Benefit Cost
	Service cost	$	14.6			$	21.7		$	15.9		$	10		$	10.3		$	10.4
	Interest cost	60.4				65.5			67.6			15.6			20.3			20.8
	Expected return on plan assets	(95.8		)		(89.6		)	(82.1		)	(21.3		)	(19.0		)	(16.9		)
	Amortization of:
	Transition obligation	—				—			—			—			0.3			0.3
	Prior service cost (credit)	2.3				2.2			2.2			(2.0		)	(1.9		)	(1.9		)
	Actuarial loss	54.5				41			34			3.7			7.3			6.2
	Settlement charge	2.5				—			—			—			—			—
	Other	—				0.4			—			—			—			—
	Net Periodic Benefit Cost	$	38.5			$	41.2		$	37.6		$	6		$	17.3		$	18.9
		Pension						OPEB
		2013		2012		2011		2013	2012		2011
	Weighted-Average assumptions used to
	determine benefit obligations as of Dec. 31
	Discount rate	5.00%		4.10%		5.05%		4.95%	4.15%		5.20%
	Rate of compensation increase	4.00%		4.00%		4.00%		N/A	N/A		N/A
	Weighted-Average assumptions used to
	determine net cost for year ended Dec. 31
	Discount rate	4.10%		5.05%		5.60%		4.15%	5.20%		5.70%
	Expected return on plan assets	7.25%		7.25%		7.25%		7.50%	7.50%		7.50%
	Rate of compensation increase	4.00%		4.00%		4.00%		N/A	N/A		N/A
	Assumed health care cost trend rates as of Dec. 31		2013		2012		2011
	Health care cost trend rate assumed for next year (Pre 65 / Post 65)		7.5%/7.5%		7.5%/7.5%		8.0%/12%
	Rate that the cost trend rate gradually adjusts to		5.00%		5.00%		5.00%
	Year that the rate reaches the rate it is assumed to remain at (Pre 65 / Post 65)		2021/2021		2017/2017		2017/2017
	The expecte
A one-percentage-point change in assumed health care cost trend rates effects	'
	A one-percentage-point change in assumed health care cost trend rates would have the following effects:
		1% Increase				1% Decrease
		(Millions of Dollars)
	Effect on
	Post-retirement benefit obligation	$	26.4			$	(22.3	)
	Total of service and interest cost components	$	3.2			$	(2.6	)
Summary of fair value of plan assets by asset category within fair value hierarchy	'
	The following table summarizes the fair value of our pension plan assets by asset category within the fair value hierarchy (for further level information, see Note M):
			As of December 31, 2013
	Asset Category - Pension		Level 1				Level 2			Level 3			Total
			(Millions of Dollars)
	Cash and Cash Equivalents		$	21			$	—		$	—		$	21
	Equities:
	U.S. Equity		519.5				—			—			519.5
	International Equity		146.2				35.7			—			181.9
	Fixed Income
	Short, Intermediate and Long-term Bonds (a)
	U.S. Bonds		108.4				505.2			—			613.6
	International Bonds		78.1				36.9			—			115
	Total		$	873.2			$	577.8		$	—		$	1,451.00
			As of December 31, 2012
	Asset Category - Pension		Level 1				Level 2			Level 3			Total
			(Millions of Dollars)
	Cash and Cash Equivalents		$	13.7			$	—		$	—		$	13.7
	Equities:
	U.S. Equity		466.3				—			—			466.3
	International Equity		134.7				30.4			—			165.1
	Fixed Income
	Short, Intermediate and Long-term Bonds (a)
	U.S. Bonds		67.7				546.6			—			614.3
	International Bonds		80.7				45.3			—			126
	Total		$	763.1			$	622.3		$	—		$	1,385.40
	(a)	This category represents investment grade bonds of U.S. and foreign issuers denominated in U.S. dollars from diverse industries.
	The following table summarizes the fair value of our OPEB plan assets by asset category within the fair value hierarchy:
			As of December 31, 2013
	Asset Category - OPEB		Level 1				Level 2			Level 3			Total
			(Millions of Dollars)
	Cash and Cash Equivalents		$	2.6			$	—		$	—		$	2.6
	Equities:
	U.S. Equity		148				—			—			148
	International Equity		46.9				2.8			—			49.7
	Fixed Income:
	Short, Intermediate and Long-term Bonds (a)
	U.S. Bonds		8.4				96.3			—			104.7
	International Bonds		16.8				5.8			—			22.6
	Total		$	222.7			$	104.9		$	—		$	327.6
			As of December 31, 2012
	Asset Category - OPEB		Level 1				Level 2			Level 3			Total
			(Millions of Dollars)
	Cash and Cash Equivalents		$	1.7			$	—		$	—		$	1.7
	Equities:
	U.S. Equity		125.9				—			—			125.9
	International Equity		39.9				2.2			—			42.1
	Fixed Income:
	Short, Intermediate and Long-term Bonds (a)
	U.S. Bonds		5				89.9			—			94.9
	International Bonds		15.4				5.4			—			20.8
	Total		$	187.9			$	97.5		$	—		$	285.4
	(a)	This category represents investment grade bonds of U.S. and foreign issuers denominated in U.S. dollars from diverse industries.
Employer contributions to defined benefit plan	'
	Cash Flows:
	Historical employer contributions:
			Pension
	Year		Qualified				Non-Qualified			OPEB
			(Millions of Dollars)
	2011		$	236.4			$	6.5		$	48.4
	2012		$	95.6			$	7.1		$	17.7
	2013		$	—			$	8.7		$	14.1
Expected benefit payments in future	'
	Estimated benefit payments:
	Year		Pension				Gross OPEB
			(Millions of Dollars)
	2014		$	103.9			$	24.2
	2015		$	98.6			$	21.6
	2016		$	100.3			$	22
	2017		$	100.9			$	22.6
	2018		$	100.2			$	23.4
	2019-2023		$	495.6			$	119.7

Segment_Reporting_Tables

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting (Tables) [Abstract]	'
Financial information of reportable operating segments	'
	Summarized financial information concerning our reportable segments for each of the three years ended December 31, 2013 is shown in the following table.
			Reportable Segments							Eliminations
			Energy				Corporate &			& Reconciling			Total
	Year Ended		Utility		Non-Utility		Other (a)			Items			Consolidated
			(Millions of Dollars)
	December 31, 2013
	Operating Revenues (b)		$	4,462.00	$	446.7	$	1.3		$	(391.0	)	$	4,519.00
	Depreciation and Amortization		$	320.2	$	67.1	$	0.8		$	—		$	388.1
	Operating Income (Loss)		$	719.4	$	367.1	$	(6.4	)	$	—		$	1,080.10
	Equity in Earnings of Unconsolidated Affiliates		$	68.5	$	—	$	(0.1	)	$	—		$	68.4
	Interest Expense, Net		$	136.2	$	65.7	$	50.8		$	(0.6	)	$	252.1
	Income Tax Expense (Benefit)		$	243.6	$	120.2	$	(25.9	)	$	—		$	337.9
	Net Income (Loss)		$	425.1	$	181.6	$	577.2		$	(606.5	)	$	577.4
	Capital Expenditures		$	657.9	$	26.1	$	3.4		$	—		$	687.4
	Total Assets (c)		$	14,460.40	$	2,846.50	$	4,719.50		$	(7,257.0	)	$	14,769.40
	December 31, 2012
	Operating Revenues (b)		$	4,190.80	$	439.9	$	1.2		$	(385.5	)	$	4,246.40
	Depreciation and Amortization		$	296.4	$	67.1	$	0.7		$	—		$	364.2
	Operating Income (Loss)		$	647.7	$	358.8	$	(6.2	)	$	—		$	1,000.30
	Equity in Earnings of Unconsolidated Affiliates		$	65.7	$	—	$	(0.2	)	$	—		$	65.5
	Interest Expense, Net		$	129.4	$	66.7	$	52.5		$	(0.4	)	$	248.2
	Income Tax Expense (Benefit)		$	214.9	$	116.6	$	(25.2	)	$	—		$	306.3
	Net Income (Loss)		$	400.6	$	175.9	$	546.1		$	(576.3	)	$	546.3
	Capital Expenditures		$	697.3	$	5.5	$	4.2		$	—		$	707
	Total Assets (c)		$	13,988.10	$	2,903.50	$	4,431.40		$	(7,038.0	)	$	14,285.00
	December 31, 2011
	Operating Revenues (b)		$	4,431.50	$	435.1	$	0.9		$	(381.1	)	$	4,486.40
	Depreciation and Amortization		$	257	$	72.5	$	0.7		$	—		$	330.2
	Operating Income (Loss)		$	544.8	$	348.9	$	(6.4	)	$	—		$	887.3
	Equity in Earnings of Unconsolidated Affiliates		$	62.5	$	—	$	(0.9	)	$	—		$	61.6
	Interest Expense, Net		$	110	$	66.7	$	59.5		$	(0.4	)	$	235.8
	Income Tax Expense (Benefit)		$	182.7	$	112.8	$	(31.6	)	$	—		$	263.9
	Income from Discontinued Operations, Net of Tax		$	—	$	—	$	13.4		$	—		$	13.4
	Net Income (Loss)		$	376.3	$	169.8	$	525.9		$	(545.8	)	$	526.2
	Capital Expenditures		$	792.2	$	31.2	$	7.4		$	—		$	830.8
	Total Assets (c)		$	13,433.50	$	2,949.00	$	4,694.80		$	(7,215.2	)	$	13,862.10
	(a)	Corporate & Other includes all other non-utility activities, primarily non-utility real estate investment and development by Wispark as well as interest on corporate debt.
	(b)	An elimination for intersegment revenues is included in Operating Revenues. This elimination is primarily between We Power and Wisconsin Electric.
	(c)	An elimination of $2,231.2 million, $2,286.7 million and $2,369.0 million is included in Total Assets as of December 31, 2013, 2012 and 2011, respectively, for all PTF-related activity between We Power and Wisconsin Electric.

Related_Parties_Material_relat

Related Parties Material related party transactions (Tables)	12 Months Ended
	Dec. 31, 2013
Material Related Party Transactions [Abstract]	'
Provided and received services from the associated companies	'
	RELATED PARTIES
	We receive and/or provide certain services to other associated companies in which we have an equity investment.
	American Transmission Company LLC:   As of December 31, 2013, we have a 26.2% interest in ATC. We pay ATC for transmission and other related services it provides. In addition, we provide a variety of operational, maintenance and project management work for ATC, which is reimbursed to us by ATC. We are required to pay the cost of needed transmission infrastructure upgrades for new generation projects while projects are under construction, including the generating units constructed as part of our PTF strategy. ATC reimburses us for these costs when new generation is placed in service.
	The following table summarizes material related party transactions with ATC during 2013, 2012 and 2011:
	Equity Investee	2013		2012		2011
		(Millions of Dollars)
	Equity in Earnings	$	68.5	$	65.7	$	62.5
	Distributions Received	$	54.5	$	52.6	$	49.7
	Services Provided	$	9	$	8.2	$	10.8
	Services Received	$	234.2	$	222.7	$	219.2
	As of December 31, 2013 and 2012, our Consolidated Balance Sheets included receivable and payable balances with ATC as follows:
	Equity Investee	2013		2012
		(Millions of Dollars)
	Accounts Receivable
	Services provided	$	0.6	$	0.5
	Accounts Payable
	Services received	$	19.5	$	18.6
Receivable and payable balances with ATC	'
	As of December 31, 2013 and 2012, our Consolidated Balance Sheets included receivable and payable balances with ATC as follows:
	Equity Investee	2013		2012
		(Millions of Dollars)
	Accounts Receivable
	Services provided	$	0.6	$	0.5
	Accounts Payable
	Services received	$	19.5	$	18.6
Material related party transactions with ATC [Table Text Block]	'
	The following table summarizes material related party transactions with ATC during 2013, 2012 and 2011:
	Equity Investee	2013		2012		2011
		(Millions of Dollars)
	Equity in Earnings	$	68.5	$	65.7	$	62.5
	Distributions Received	$	54.5	$	52.6	$	49.7
	Services Provided	$	9	$	8.2	$	10.8
	Services Received	$	234.2	$	222.7	$	219.2

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies (Tables) [Abstract]	'
Future minimum payments for the next five years and thereafter for our operating lease contracts	'
	Future minimum payments for the next five years and thereafter for our operating lease contracts are as follows:
		(Millions of Dollars)
	2014	$	3.9
	2015	3.9
	2016	3.7
	2017	3.1
	2018	3.2
	Thereafter	22.7
	Total	$	40.5

Preferred_Stock_Tables

Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2013
Preferred Stock [Abstract]	'
Preferred Stock [Text Block]	'
	PREFERRED STOCK
	The following table shows preferred stock authorized and outstanding at December 31, 2013 and 2012:
		Shares Authorized	Shares Outstanding	Redemption Price Per Share		Total
						(In Millions)
	Wisconsin Energy
	$.01 par value Preferred Stock	15,000,000	—	—		$	—
	Wisconsin Electric
	$100 par value, Six Per Cent. Preferred Stock	45,000	44,498	—		$	4.4
	$100 par value, Serial Preferred Stock	2,286,500
	3.60% Series		260,000	$	101	26
	$25 par value, Serial Preferred Stock	5,000,000	—	—		—
	Total preferred stock of subsidiary					$	30.4

Recovered_Sheet2

Summary Of Significant Accounting Policies (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Public Utilities, Disclosure of Rate Matters	'Our retail electric rates in Wisconsin are established by the PSCW and include base amounts for fuel and purchased power costs. The electric fuel rules in Wisconsin allow us to defer, for subsequent rate recovery or refund, any under-collection or over-collection of fuel costs that are outside of the symmetrical fuel cost tolerance, which the PSCW set at plus or minus 2% of the approved fuel cost plan. The deferred under-collected amounts are subject to an excess revenues test. Our retail gas rates include monthly adjustments which permit the recovery or refund of actual purchased gas costs. We defer any difference between actual gas costs incurred (adjusted for a sharing mechanism) and costs recovered through rates as a current asset or liability. The deferred balance is returned to or recovered from customers at intervals throughout the year.	'	'
Goodwill	$441.90	$441.90	'
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	2.90%	2.90%	2.80%
Regulatory liabilities	879.1	868.3	'
Equity Method Investment, Ownership Percentage	50.00%	'	'
PWGS 1 [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Depreciation over an estimated useful life	'10 to 45 years	'	'
PWGS 2 [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Depreciation over an estimated useful life	'10 to 45 years	'	'
OC 1 [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Depreciation over an estimated useful life	'10 to 55 years	'	'
OC 2 [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Depreciation over an estimated useful life	'10 to 55 years	'	'
Asset Retirement Obligation Costs [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Regulatory liabilities	$724.50	$725	'
Transmission Affiliate [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Equity Method Investment, Ownership Percentage	'	26.20%	'
Maximum [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Risk-free interest rate	1.90%	2.00%	3.40%
Minimum [Member]	'	'	'
Public Utility Property Plant And Equipment [Line Items]	'	'	'
Risk-free interest rate	0.10%	0.10%	0.20%

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details 1)	12 Months Ended
	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]	'
Equity Method Investment, Ownership Percentage	50.00%
ATC [Member]	'
Schedule of Equity Method Investments [Line Items]	'
Equity Method Investment, Ownership Percentage	26.20%
Voting rights in ATC board members	'one out of ten
Number of votes with each member of ATC	'1
Maximum voting control for individual member in ATC	10.00%

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Property in Service by Segment	'	'
Property In Service	$14,966.30	$14,238.80
Construction Work in Progress (CWIP) by segment	'	'
Construction Work in Progress (CWIP)	149.6	315.9
Goodwill related to acquisition of Wisconsin Gas	441.9	441.9
Utility Energy [Member]	'	'
Property in Service by Segment	'	'
Property In Service	11,779.80	11,080.90
Construction Work in Progress (CWIP) by segment	'	'
Construction Work in Progress (CWIP)	132.7	298.2
Non-Utility Energy [Member]	'	'
Property in Service by Segment	'	'
Property In Service	3,091.30	3,068.50
Construction Work in Progress (CWIP) by segment	'	'
Construction Work in Progress (CWIP)	16.5	13.3
Corporate and Other [Member]	'	'
Property in Service by Segment	'	'
Property In Service	95.2	89.4
Construction Work in Progress (CWIP) by segment	'	'
Construction Work in Progress (CWIP)	$0.40	$4.40

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'
Debt Securities In Cash Equivalents, Maximum Period Until Maturity	'0 years 3 months	'	'
Fuel Cost Tolerance Range Set by Regulators, Percent	2.00%	'	'
Regulatory liabilities	$879.10	$868.30	'
Fair value of stock options	'	'	'
Dividend yield	3.70%	3.90%	3.90%
Expected volatility	18.00%	19.00%	19.00%
Expected life (years)	'5 years 11 months	'5 years 11 months	'5 years 6 months
Expected forfeiture rate	2.00%	2.00%	2.00%
Weighted average fair value of our stock options granted	$3.45	$3.34	$3.17
Other Income and Deductions, Net	'	'	'
AFUDC - Equity	18.3	35.3	59.4
Other, net	0.5	-0.5	3.3
Other Income and Deductions, net	18.8	34.8	62.7
Allowance For Funds Used During Construction	'	'	'
AFUDC - Debt	7.7	14.7	24.7
AFUDC - Equity	18.3	35.3	59.4
Inventories	'	'	'
Fossil Fuel	117.7	165.5	'
Materials and Supplies	133.9	121.9	'
Natural Gas in Storage	77.8	73.3	'
Total	329.4	360.7	'
Summary Of Significant Accounting Policies (Additional) (Textuals) [Abstract]	'	'	'
Symmetrical Fuel Cost Tolerance Range Set By Regulatory Authority	'Our retail electric rates in Wisconsin are established by the PSCW and include base amounts for fuel and purchased power costs. The electric fuel rules in Wisconsin allow us to defer, for subsequent rate recovery or refund, any under-collection or over-collection of fuel costs that are outside of the symmetrical fuel cost tolerance, which the PSCW set at plus or minus 2% of the approved fuel cost plan. The deferred under-collected amounts are subject to an excess revenues test. Our retail gas rates include monthly adjustments which permit the recovery or refund of actual purchased gas costs. We defer any difference between actual gas costs incurred (adjusted for a sharing mechanism) and costs recovered through rates as a current asset or liability. The deferred balance is returned to or recovered from customers at intervals throughout the year.	'	'
Reclassification of deferred tax assets	59	'	'
Depreciation percentage of average depreciable utility plant	2.90%	2.90%	2.80%
Maximum duration to recover outstanding regulatory assets	'8 years	'	'
Minimum duration to recover outstanding regulatory assets	'1 year	'	'
Impairment charges related to goodwill	0	'	'
Long-lived assets held for sale	0	'	'
Revenue from Grants	48	0	0
Grants Receivable, Current	$82.60	'	'
Stock Options [Member]	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'
Expiration of options from time of grant	'10 years	'	'
Fair value of stock options	'	'	'
Weighted average fair value of our stock options granted	$37.46	'	'

Regulatory_Assets_and_Liabilit2

Regulatory Assets and Liabilities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Regulatory Assets [Line Items]	'	'
Regulatory assets earnings return based on short-term rates	$82.70	'
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	10.1	'
Regulatory Assets	'	'
Regulatory Assets	1,108.50	1,380.30
Deferred unrecognized pension costs [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	537.6	731.5
Deferred income tax related [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	169.5	176.5
Escrowed electric transmission costs [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	126.8	114.1
Escrowed conservation [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	66.9	73.5
Deferred plant related -- capital lease [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	56.5	66.6
Deferred environmental costs [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	47	47.4
Other, net [Member]	'	'
Regulatory Assets	'	'
Regulatory Assets	$104.20	$170.70

Regulatory_Assets_and_Liabilit3

Regulatory Assets and Liabilities (Details 1) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Regulatory Liabilities [Line Items]	'	'
Regulatory liabilities	$879.10	$868.30
Deferred cost of removal obligations [Member]	'	'
Regulatory Liabilities [Line Items]	'	'
Regulatory liabilities	724.5	725
Escrowed Bad Debt Costs [Member]	'	'
Regulatory Liabilities [Line Items]	'	'
Regulatory liabilities	64.6	81.1
Other, net [Member]	'	'
Regulatory Liabilities [Line Items]	'	'
Regulatory liabilities	$90	$62.20

Asset_Sales_Divestitures_And_D1

Asset Sales, Divestitures And Discontinued Operations (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Net impacts of the discontinued operations on earnings	'		'		'
Income from Continuing Operations	$577.40		$546.30		$512.80
Income from Discontinued Operations, Net of Tax	0		0		13.4
Net Income	577.4		546.3		526.2
Asset Sales, Divestitures and Discontinued Operations (Textuals) [Abstract]	'		'		'
Ownership percentage in Edgewater Generating Unit 5 sold	'		'		25.00%
Proceeds From Sale Of Interest In Unit	'		'		38
Other Operations [Member]	'		'		'
Net impacts of the discontinued operations on earnings	'		'		'
Income from Discontinued Operations, Net of Tax	$0	[1]	$0	[1]	$13.40	[1]
[1]	Primarily relates to the favorable resolution of uncertain state and federal tax positions associated with our previously discontinued manufacturing business.

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Change in Asset Retirement Obligations	'	'
Balance as of January 1	$44.30	$55.50
Liabilities settled	-4.4	-14
Accretion	2.4	2.8
Balance as of December 31	$42.30	$44.30

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Megawatt
Variable Interest Entities (Textuals)	'	'	'
Power capacity from a gas-fired cogeneration facility under capital lease (MW)	236	'	'
Capital lease agreement with VIE remaining term in years	'9 years	'	'
Total payments over remaining terms of the two agreements	$215.90	'	'
Total capacity and minimum lease payments	$50.30	$45.80	$65.90

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of income tax expense	'	'	'
Current tax expense (benefit)	$25.20	$13.10	($166.70)
Deferred income taxes, net	313.8	294.4	434.8
Investment tax credit, net	-1.1	-1.2	-4.2
Total Income Tax Expense, Amount	337.9	306.3	263.9
The provision for income taxes for each of the years ended December 31 differs from the amount of income tax determined by applying the applicable U.S. statutory federal income tax rate to income before income taxes as a result of the following:	'	'	'
Expected tax at statutory federal tax rates, Amount	320.3	298.4	271.8
Expected tax at statutory federal tax rates, Effective Tax Rate	35.00%	35.00%	35.00%
State income taxes net of federal tax benefit, Amount	49	43.3	40.1
State income taxes net of federal tax benefit, Effective Tax Rate	5.30%	5.10%	5.20%
Domestic production activities deduction, Amount	0	-12.6	-12.6
Domestic production activities deduction, Effective Tax Rate	0.00%	-1.50%	-1.60%
AFUDC - Equity, Amount	-6.4	-12.3	-20.8
AFUDC - Equity, Effective Tax Rate	-0.70%	-1.40%	-2.70%
Production tax credits - wind, Amount	-16.7	-15.9	-8.7
Production tax credits - wind, Effective Tax Rate	-1.80%	-1.90%	-1.10%
Effective Tax Rate Reconciliation, 1603 Grant, Amount	-7.4	0	0
Effective Tax Rate Reconciliation, 1603 Grant, Percent	-0.80%	0.00%	0.00%
Investment tax credit restored, Amount	-1.1	-1.2	-4.2
Investment tax credit restored, Effective Tax Rate	-0.10%	-0.10%	-0.50%
Other, net, Amount	0.2	6.6	-1.7
Other, net, Effective Tax Rate	0.00%	0.70%	-0.30%
Total Income Tax Expense, Amount	337.9	306.3	263.9
Total Income Tax Expense, Effective Tax Rate	36.90%	35.90%	34.00%
Current	'	'	'
Deferred Tax Assets, Future Federal Tax Benefits, Current	309.7	59	'
Employee benefits and compensation	13.8	14.9	'
Other	56	81.1	'
Total Current Deferred Tax Assets	379.5	155	'
Non-current	'	'	'
Deferred revenues	237	250	'
Employee benefits and compensation	95.6	97	'
Deferred Tax Assets, Future Federal Tax Benefits, Non Current	32.5	334.7	'
Property-related	28.2	28.3	'
Construction advances	18.3	22.2	'
Other	62.9	16.3	'
Total Non-current Deferred Tax Assets	474.5	748.5	'
Total Deferred Tax Assets	854	903.5	'
Current	'	'	'
Prepaid items	69.5	49.7	'
Total Current Deferred Tax Liabilities	69.5	49.7	'
Non-current	'	'	'
Property-related	2,574.40	2,339.40	'
Employee benefits and compensation	238.5	244.3	'
Investment in transmission affiliate	169.9	144.9	'
Deferred transmission costs	50.8	45.7	'
Other	74.9	91.2	'
Total Non-current Deferred Tax Liabilities	3,108.50	2,865.50	'
Total Deferred Tax Liabilities	3,178	2,915.20	'
Consolidated Balance Sheet Presentation	'	'	'
Current Deferred Tax Asset	310	105.3	'
Non-Current Deferred Tax Liability	2,634	2,117	'
Reconciliation of the beginning and ending amount of unrecognized tax benefits	'	'	'
Balance, January 1	11.3	11.1	'
Additions for tax positions of prior years	0	10.8	'
Reductions for tax positions of prior years	-2.9	-10.6	'
Balance, December 31	8.4	11.3	11.1
Income Taxes (Textuals)	'	'	'
Deferred tax assets valuation allowance	8.4	10.2	'
Net amount of unrecognized tax benefits having impact on the effective tax rate for continuing operations	0	1	'
Accrued interest in the Consolidated Income Statements	0.2	0.2	0.7
Accrued penalties in the Consolidated Income Statements	0	0	0.3
Accrued interest on the Consolidated Balance Sheets	0.4	0.3	'
Accrued penalties on the Consolidated Balance Sheets	0	0	'
Operating Loss Carryforwards	810.3	1,007.10	'
Deferred Tax Assets, Operating Loss Carryforwards	283.6	352.5	'
Tax Credit Carryforward, Amount	58.6	41.2	'
Tax Credit Carryforward, Deferred Tax Asset	$58.60	$41.20	'

Common_Equity_Details

Common Equity (Details) (USD $)	1 Months Ended				12 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'	'	'	'
Common Stock, Shares Authorized	'	'	'	'	325,000,000	325,000,000	'
Recorded pre-tax share-based compensation expense and related tax benefit for share-based awards made to employees and directors	'	'	'	'	'	'	'
Share-based compensation expense	'	'	'	'	$19	$22	$28.50
Common Equity (Textuals)	'	'	'	'	'	'	'
Actual tax benefit realized for the tax deductions from option exercises/settlement	'	'	'	'	17.8	0	14.3
Common Stock, Shares, Outstanding	'	'	'	'	225,962,959	229,039,456	'
Related Tax Benefit	'	'	'	'	7.6	8.8	11.4
Maximum [Member]	'	'	'	'	'	'	'
Common Equity (Textuals)	'	'	'	'	'	'	'
Requirement to maintain common equity ratio by Wisconsin Electric	'	'	'	'	53.50%	'	'
Requirement to maintain common equity ratio by Wisconsin Gas	'	'	'	'	50.00%	'	'
Minimum [Member]	'	'	'	'	'	'	'
Common Equity (Textuals)	'	'	'	'	'	'	'
Requirement to maintain common equity ratio by Wisconsin Electric	'	'	'	'	48.50%	'	'
Requirement to maintain common equity ratio by Wisconsin Gas	'	'	'	'	45.00%	'	'
Performance Units [Member]	'	'	'	'	'	'	'
Recorded pre-tax share-based compensation expense and related tax benefit for share-based awards made to employees and directors	'	'	'	'	'	'	'
Share-based compensation expense	'	'	'	'	12.7	16.3	24.1
Related Tax Benefit	'	'	'	'	5.3	7	9.7
Restricted stock activity	'	'	'	'	'	'	'
Granted, Number of Shares	233,735	239,120	346,570	435,690	'	'	'
Common Equity (Textuals)	'	'	'	'	'	'	'
Unrecognized total compensation costs related share based compensation	'	'	'	'	10.8	'	'
Months, on a weighted-average basis, expected for recognizing total compensation costs related to non-vested stock options	'	'	'	'	'20 months	'	'
Intrinsic Value	'	'	'	'	14.8	19.3	26.7
Stock Options [Member]	'	'	'	'	'	'	'
Recorded pre-tax share-based compensation expense and related tax benefit for share-based awards made to employees and directors	'	'	'	'	'	'	'
Share-based compensation expense	'	'	'	'	3.9	2.7	2.6
Non-Vested Options [Member]	'	'	'	'	'	'	'
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, Weighted Average Grant Date Fair Value	'	'	'	'	'	$3.31	'
Common Equity (Textuals)	'	'	'	'	'	'	'
Unrecognized total compensation costs related share based compensation	'	'	'	'	2	'	'
Months, on a weighted-average basis, expected for recognizing total compensation costs related to non-vested stock options	'	'	'	'	'21 months	'	'
Restricted Stock [Member]	'	'	'	'	'	'	'
Recorded pre-tax share-based compensation expense and related tax benefit for share-based awards made to employees and directors	'	'	'	'	'	'	'
Share-based compensation expense	'	'	'	'	2.4	3	1.8
Related Tax Benefit	'	'	'	'	1.3	0	0.8
Restricted stock activity	'	'	'	'	'	'	'
Outstanding	150,698	188,222	'	'	188,222	'	'
Granted, Number of Shares	71,504	'	'	'	74,290	'	'
Granted, Weighted-Average Market Price	'	'	'	'	$37.65	'	'
Released, Number of Shares	'	'	'	'	-97,973	'	'
Released, Weighted-Average Market Price	'	'	'	'	$26.65	'	'
Forfeited, Number of Shares	'	'	'	'	-13,841	'	'
Forfeited, Weighted-Average Market Price	'	'	'	'	$33.35	'	'
Outstanding	'	'	'	'	150,698	188,222	'
Common Equity (Textuals)	'	'	'	'	'	'	'
Unrecognized total compensation costs related share based compensation	'	'	'	'	2.6	'	'
Months, on a weighted-average basis, expected for recognizing total compensation costs related to non-vested stock options	'	'	'	'	'20 months	'	'
Restricted stock vesting period in years	'3 years	'	'	'	'	'	'
Intrinsic Value	'	'	'	'	$4	$3.50	$2.50

Common_Equity_Details_1

Common Equity (Details 1) (USD $)	1 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock option activity	'	'	'	'
Outstanding, Shares, Beginning Balance	8,089,710	'	'	'
Outstanding, Weighted-Average Exercise Price, Beginning	$26.84	'	'	'
Granted, shares	899,500	'	'	'
Granted, Weighted-Average Exercise Price	'	$3.45	$3.34	$3.17
Outstanding, Shares, Ending Balance	'	8,089,710	'	'
Outstanding, Weighted-Average Exercise Price, Ending	'	$26.84	'	'
Exercisable, shares	'	5,708,920	'	'
Exercisable, Weighted-Average Exercise Price	'	$23.16	'	'
Stock Options [Member]	'	'	'	'
Stock option activity	'	'	'	'
Outstanding, Shares, Beginning Balance	'	8,919,669	'	'
Outstanding, Weighted-Average Exercise Price, Beginning	'	$23.86	'	'
Granted, Weighted-Average Exercise Price	'	$37.46	'	'
Exercised, shares	'	-2,238,489	'	'
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	'	$21.67	'	'
Forfeited, shares	'	-10,030	'	'
Forfeited, Weighted-Average Exercise Price	'	$35.37	'	'
Outstanding, Shares, Ending Balance	'	8,089,710	'	'
Outstanding, Weighted-Average Exercise Price, Ending	'	$26.84	'	'
Outstanding, Weighted-Average Remaining Contractual Life (Years)	'	'5 years 5 months	'	'
Outstanding, Aggregate Intrinsic Value	'	$117.30	'	'
Exercisable, shares	'	5,708,920	'	'
Exercisable, Weighted-Average Exercise Price	'	$23.16	'	'
Exercisable, Weighted-Average Remaining Contractual Life (Years)	'	'4 years 1 month	'	'
Exercisable, Aggregate Intrinsic Value	'	$103.80	'	'

Common_Equity_Details_2

Common Equity (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013
Stock options outstanding	'
Options Outstanding, Number, Total	8,089,710
Options Outstanding, Weighted-Average Exercise Price	$26.84
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	'5 years 5 months
Options Exercisable, Number, Total	5,708,920
Options Exercisable, Weighted-Average Exercise Price	$23.16
Options Exercisable, Weighted-Average Remaining Contractual Life (Years)	'4 years 1 month
Exercise Price, Range One [Member]	'
Stock options outstanding	'
Options Outstanding, Number, Total	2,128,370
Options Outstanding, Weighted-Average Exercise Price	$20.34
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	'3 years 11 months
Options Exercisable, Number, Total	2,128,370
Options Exercisable, Weighted-Average Exercise Price	$20.34
Options Exercisable, Weighted-Average Remaining Contractual Life (Years)	'3 years 11 months
Exercise Price, Range One [Member] | Maximum [Member]	'
Stock options outstanding	'
Options Outstanding, Weighted-Average Exercise Price	$21.11
Exercise Price, Range One [Member] | Minimum [Member]	'
Stock options outstanding	'
Options Outstanding, Weighted-Average Exercise Price	$16.72
Exercise Price, Range Two [Member]	'
Stock options outstanding	'
Options Outstanding, Number, Total	3,689,900
Options Outstanding, Weighted-Average Exercise Price	$24.65
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	'4 years 2 months
Options Exercisable, Number, Total	3,382,630
Options Exercisable, Weighted-Average Exercise Price	$24.23
Options Exercisable, Weighted-Average Remaining Contractual Life (Years)	'4 years 0 months
Exercise Price, Range Two [Member] | Maximum [Member]	'
Stock options outstanding	'
Options Outstanding, Weighted-Average Exercise Price	$29.35
Exercise Price, Range Two [Member] | Minimum [Member]	'
Stock options outstanding	'
Options Outstanding, Weighted-Average Exercise Price	$23.88
Exercise Price, Range Three [Member]	'
Stock options outstanding	'
Options Outstanding, Number, Total	2,271,440
Options Outstanding, Weighted-Average Exercise Price	$36.48
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	'8 years 7 months
Options Exercisable, Number, Total	197,920
Options Exercisable, Weighted-Average Exercise Price	$35.19
Options Exercisable, Weighted-Average Remaining Contractual Life (Years)	'8 years 1 month
Exercise Price, Range Three [Member] | Maximum [Member]	'
Stock options outstanding	'
Options Outstanding, Weighted-Average Exercise Price	$37.46
Exercise Price, Range Three [Member] | Minimum [Member]	'
Stock options outstanding	'
Options Outstanding, Weighted-Average Exercise Price	$34.88

Common_Equity_Details_3

Common Equity (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Non-vested options	'	'	'
Granted, Weighted-Average Exercise Price	$3.45	$3.34	$3.17
Outstanding, Shares, Ending Balance	8,089,710	'	'
Outstanding, Weighted-Average Exercise Price, Ending	$26.84	'	'
Non-Vested 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, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	'	$3.31	'
Non-vested options	'	'	'
Outstanding, Shares, Beginning Balance	1,702,275	'	'
Granted, shares	1,418,560	'	'
Granted, Weighted-Average Exercise Price	$3.45	'	'
Vested, shares	-730,015	'	'
Vested, Weighted-Average Exercise Price	$3.34	'	'
Forfeited, shares	-10,030	'	'
Forfeited, Weighted-Average Exercise Price	$3.37	'	'
Outstanding, Shares, Ending Balance	2,380,790	'	'
Outstanding, Weighted-Average Exercise Price, Ending	$3.38	'	'

Common_Equity_Details_4

Common Equity (Details 4) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

32 Months Ended

12 Months Ended

Jan. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

31-May-11

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Share Repurchase Plan, 2014 - 2017 [Member] [Domain]

Share Repurchase Plan, 2011 [Member]

Share Repurchase Plan, 2011 [Member]

Share Repurchases to Fulfill Exercised Stock Options and Restricted Stock Awards [Member]

Share Repurchases to Fulfill Exercised Stock Options and Restricted Stock Awards [Member]

Share Repurchases to Fulfill Exercised Stock Options and Restricted Stock Awards [Member]

Share Repurchase Plan, 2011 [Member]

Share Repurchase Plan, 2011 [Member]

Share Repurchase Plan, 2011 [Member]

Stock Options [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Repurchased During Period, Shares

'

5,400,000

4,300,000

6,200,000

'

'

'

2,400,000

2,800,000

3,000,000

3,000,000

1,500,000

3,200,000

'

Common Equity (Textuals)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock shares, Authorized

'

325,000,000

325,000,000

'

'

'

'

'

'

'

'

'

'

'

Common stock shares, Outstanding

'

225,962,959

229,039,456

'

'

'

'

'

'

'

'

'

'

'

Stock options awarded under long-term incentive compensation

'

'

'

'

'

'

'

'

'

'

'

'

'

1,418,560

Exercise price of non qualified stock options

$41.03

'

'

'

'

'

'

'

'

'

'

'

'

'

Intrinsic value of options exercised

'

$44,500,000

$47,500,000

$36,100,000

'

'

'

'

'

'

'

'

'

'

Exercise price of the stock option on the grant date

'

'no less than 100% of the common stock's fair market value

'

'

'

'

'

'

'

'

'

'

'

'

Mimimum period after grant that stock options can be exercised

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 months

Expiration of options from time of grant

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

Minimum percentage award based on performance unit

'

0

'

'

'

'

'

'

'

'

'

'

'

'

Maximum percentage award based on performance unit

'

1.75

'

'

'

'

'

'

'

'

'

'

'

'

Amount paid for Shares Purchased by agents from open market

'

223,400,000

153,200,000

193,900,000

'

'

'

'

'

'

'

'

'

'

Exercise of stock options

'

48,500,000

49,800,000

54,400,000

'

'

'

'

'

'

'

'

'

'

Maximum period to defer interest payments on the Junior Notes

'

'We have the option to defer interest payments on the Junior Notes, from time to time, for one or more periods of up to 10 consecutive years per period. During any period in which we defer interest payments, we may not declare or pay any dividends or distributions on, or redeem, repurchase or acquire, our common stock.

'

'

'

'

'

'

'

'

'

'

'

'

Ability to declare common dividends limited to Percentage of Net Income by Wisconsin Electric

'

'limited to 75% or 50%

'

'

'

'

'

'

'

'

'

'

'

'

Wisconsin Electric's common stock equity to total capitalization

'

'is less than 25% and 20%

'

'

'

'

'

'

'

'

'

'

'

'

3.60% Serial Preferred Stock

'

3.60%

'

'

'

'

'

'

'

'

'

'

'

'

Maximum percentage of equity method investment

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

Equity method investment

'

3,600,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of equity method investment exceeding consolidated net assets

'

25.00%

'

'

'

'

'

'

'

'

'

'

'

'

Stock Repurchase Program, Authorized Amount

'

'

'

'

300,000,000

300,000,000

'

'

'

'

'

'

'

'

Stock Repurchased and Retired During Period, Shares

'

'

'

'

'

'

7,700,000

'

'

'

'

'

'

'

Treasury Stock Acquired, Average Cost Per Share

'

'

'

'

'

'

$36.19

'

'

'

'

'

'

'

Treasury Stock, Value, Acquired, Cost Method

'

'

'

'

'

'

277,800,000

'

'

'

'

'

'

'

Stock Repurchased During Period, Value

'

$223,400,000

$153,200,000

$193,900,000

'

'

'

$97,400,000

$101,400,000

$93,900,000

$126,000,000

$51,800,000

$100,000,000

'

LongTerm_Debt_and_Capital_Leas2

Long-Term Debt and Capital Lease Obligations (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2009
	Megawatt
Long-term debt outstanding maturities and sinking fund requirements	'		'		'	'
Next year	$322.40		'		'	'
Year 2	399.5		'		'	'
Year 3	27.4		'		'	'
Year 4	29.5		'		'	'
Year 5	281.1		'		'	'
Thereafter	3,566.80		'		'	'
Total	4,626.70		'		'	'
Summary of capitalized leased facilities	'		'		'	'
Long-term power purchase commitment	140.3		140.3		'	'
Accumulated amortization	-92.5		-86.8		'	'
Total Leased Facilities	47.8		53.5		'	'
Future minimum lease payments under capital lease and present value of net minimum lease payments	'		'		'	'
Due next year	41.9		'		'	'
Due in two years	43.5		'		'	'
Due in three years	45.1		'		'	'
Due in four years	13.9		'		'	'
Due in five years	14.7		'		'	'
Thereafter	56.8		'		'	'
Total Minimum Lease Payments	215.9		'		'	'
Less: Estimated Executory Costs	-61.7		'		'	'
Capital Leases Future Minimum Payments Due, Less Executory Costs	154.2		'		'	'
Less: Interest	-49.9		'		'	'
Net Minimum Lease Payments	104.3		'		'	'
Less: Due Currently	-19.8		'		'	'
Future minimum lease payments under our capital lease and the present value of our net minimum lease payments	84.5		'		'	'
Long-Term Debt and Capital Lease Obligations (Textuals) [Abstract]	'		'		'	'
Issuance of long-term debt	251		251.8		720	'
Number of series of tax-exempt pollution control refunding bonds	2		'		'	'
Restriction under RCC	'The RCC provides that we may not redeem, defease or purchase and our subsidiaries may not purchase any Junior Notes on or before May 15, 2037, unless, subject to certain limitations described in the RCC, during the 180 days prior to the date of redemption, defeasance or purchase, we have received a specified amount of proceeds from the sale of qualifying securities.		'		'	'
Period of Power purchase contract with an unaffiliated independent power producer	'25 years		'		'	'
Power capacity from a gas-fired cogeneration facility under capital lease (MW)	236		'		'	'
Minimum energy requirement in gas-fired cogeneration facility	0		'		'	'
Power purchase contract expiration year	31-Dec-22		'		'	'
Power purchase contract expected future renewable period	'10 years		'		'	'
Total operating lease payment	33.7		32.5		'	'
Increase in regulatory asset due to minimum lease payment	'		'		'	78.5
Regulatory asset value at the end of life of contract	0		'		'	'
Total capital lease obligation	104.3		120		'	'
Capital lease obligation at the end of life of contract	0		'		'	'
Notes (secured, nonrecourse), 6.09% due 2030-2040 [Member]	'		'		'	'
Long-Term Debt and Capital Lease Obligations (Textuals) [Abstract]	'		'		'	'
Secured Long-term Debt, Noncurrent	275	[1]	275	[1]	'	'
Debt instrument interest rate stated percentage rate	6.09%		6.09%		'	'
Notes (unsecured), 6.20% due 2033 [Member]	'		'		'	'
Long-Term Debt and Capital Lease Obligations (Textuals) [Abstract]	'		'		'	'
Unsecured Long-term Debt, Noncurrent	200		200		'	'
Debt instrument interest rate stated percentage rate	6.20%		6.20%		'	'
Parent Company [Member]	'		'		'	'
Long-term debt outstanding maturities and sinking fund requirements	'		'		'	'
Next year	0		'		'	'
Year 2	0		'		'	'
Year 3	0		'		'	'
Year 4	0		'		'	'
Year 5	0		'		'	'
Thereafter	700		'		'	'
Total	700		'		'	'
Wisconsin Electric [Member]	'		'		'	'
Long-Term Debt and Capital Lease Obligations (Textuals) [Abstract]	'		'		'	'
Unsecured Long-term Debt, Noncurrent	$147		$147		'	'
[1]	(c) Senior notes are secured by a collateral assignment of the leases between ERGSS and Wisconsin Electric related to OC 1 and 2.

ShortTerm_Debt_Details

Short-Term Debt (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Short-Term Debt (Textuals) [Abstract]	'	'
Undrawn lines under bank back-up credit facilities	$1,200,000,000	'
Short-term debt outstanding supported by the available lines of credit	537,400,000	'
Wisconsin Energy Corporation [Member]	'	'
Short-Term Debt (Textuals) [Abstract]	'	'
Minimum total funded debt to capitalization ratio	70.00%	'
Wisconsin Electric [Member]	'	'
Short-Term Debt (Textuals) [Abstract]	'	'
Minimum total funded debt to capitalization ratio	65.00%	'
Wisconsin Gas [Member]	'	'
Short-Term Debt (Textuals) [Abstract]	'	'
Minimum total funded debt to capitalization ratio	65.00%	'
Commercial Paper [Member]	'	'
Short-term notes payable balances and their corresponding weighted-average interest rates	'	'
Commercial paper, balance	537,400,000	394,600,000
Commercial paper, weighted-average interest rate	0.20%	0.30%
Commercial paper [Abstract]	'	'
Maximum Short-Term Debt Outstanding	594,500,000	669,900,000
Average Short-Term Debt Outstanding	$359,100,000	$481,600,000
Weighted-Average Interest Rate	0.25%	0.28%

Derivative_Instruments_Details

Derivative Instruments (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivatives Fair Value [Line Items]	'	'
Derivative, Asset	$11.80	$19.20
Derivative, Liability	0.3	1.9
Gains (losses)	6.9	-28.4
Other Deferred Charges and Other Assets [Member]	'	'
Derivatives Fair Value [Line Items]	'	'
Long-term portion of derivative assets	0.4	'
Other Long-Term Liabilities [Member]	'	'
Derivatives Fair Value [Line Items]	'	'
Long-term portion of derivative liabilities	0	'
Natural Gas [Member]	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative, Asset	5.6	3
Derivative, Liability	0.1	1.9
Volume	'48.6 million Dth	'77.2 million Dth
Gains (losses)	-8.5	-36.3
Fuel Oil [Member]	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative, Asset	0.6	0.4
Derivative, Liability	0	0
Volume	'8.6 million gallons	'7.0 million gallons
Gains (losses)	0.5	1.8
FTRs [Member]	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative, Asset	3.5	4.7
Derivative, Liability	0	0
Volume	'25.3 million MWh	'25.1 million MWh
Gains (losses)	14.9	6.1
Coal [Member]	'	'
Derivatives Fair Value [Line Items]	'	'
Derivative, Asset	2.1	11.1
Derivative, Liability	$0.20	$0

Derivative_Instruments_Details1

Derivative Instruments (Details 1) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Regulatory Assets [Line Items]	'	'
Regulatory assets related to derivatives	$1,108.50	$1,380.30
Derivative [Member]	'	'
Regulatory Assets [Line Items]	'	'
Regulatory assets related to derivatives	$0.30	$7.60

Derivative_Instruments_Details2

Derivative Instruments (Details 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Regulatory Liabilities [Line Items]	'	'
Regulatory liabilities related to derivatives	$879.10	$868.30
Derivative [Member]	'	'
Regulatory Liabilities [Line Items]	'	'
Regulatory liabilities related to derivatives	$9.60	$17.50

Derivative_Instruments_Details3

Derivative Instruments (Details 3) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]	'	'	'
Collateral in margin accounts	$0	$2.90	'
Derivative Asset	11.8	19.2	'
Derivative Liability	0.3	1.9	'
Reclassification in treasury lock agreement settlement payments deferred in Accumulated Other Comprehensive Income as increase to interest Expense	252.1	248.2	235.8
Derviative Instrument by Counterparty, Gross Amount Recognized on Balance Sheet [Member]	'	'	'
Derivative [Line Items]	'	'	'
Derivative Asset	11.8	19.2	'
Derivative Liability	0.3	1.9	'
Derviative Instrument by Counterparty, Gross Amount Not Offset on Balance Sheet [Member] [Member]	'	'	'
Derivative [Line Items]	'	'	'
Collateral in margin accounts	0	1.3	'
Derivative Asset	0	-0.5	'
Derivative Liability	0	-1.8	'
Derviative Instrument by Counterparty, Net Amount [Member]	'	'	'
Derivative [Line Items]	'	'	'
Derivative Asset	11.8	18.7	'
Derivative Liability	$0.30	$0.10	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets:	'	'
Restricted Cash	'	$2.70
Derivative, Asset	11.8	19.2
Total	11.8	21.9
Liabilities:	'	'
Derivative, Liability	0.3	1.9
Total	0.3	1.9
Fair Value, Inputs, Level 1 [Member]	'	'
Assets:	'	'
Restricted Cash	'	2.7
Derivative, Asset	5.7	2.2
Total	5.7	4.9
Liabilities:	'	'
Derivative, Liability	0	1.9
Total	0	1.9
Fair Value, Inputs, Level 2 [Member]	'	'
Assets:	'	'
Restricted Cash	'	0
Derivative, Asset	2.6	12.3
Total	2.6	12.3
Liabilities:	'	'
Derivative, Liability	0.3	0
Total	0.3	0
Fair Value, Inputs, Level 3 [Member]	'	'
Assets:	'	'
Restricted Cash	'	0
Derivative, Asset	3.5	4.7
Total	3.5	4.7
Liabilities:	'	'
Derivative, Liability	0	0
Total	$0	$0

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 1) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair value of derivatives classified as Level 3 in the fair value hierarchy	'	'
Change in unrealized gains (losses) relating to instruments still held as of December 31	$0	$0
Derivative [Member]	'	'
Fair value of derivatives classified as Level 3 in the fair value hierarchy	'	'
Beginning Balance	4.7	5.7
Realized and unrealized gains (losses)	0	0
Purchases	10.6	11
Issuances	0	0
Settlements	-11.8	-12
Transfers in and/or out of Level 3	0	0
Ending Balance	$3.50	$4.70

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Instruments	'	'
Preferred Stock	$30.40	$30.40
Long-term debt including current portion, carrying value	4,626.70	4,772.90
Long-term debt including current portion, fair value	4,911.80	5,447.30
Fair Value [Member]	'	'
Financial Instruments	'	'
Preferred Stock	26	26
Carrying Amount [Member]	'	'
Financial Instruments	'	'
Preferred Stock	$30.40	$30.40

Benefits_Details

Benefits (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans [Member]	'	'	'
Change in Benefit Obligation	'	'	'
Benefit Obligation at January 1	$1,508.50	$1,330.60	'
Service cost	14.6	21.7	15.9
Interest cost	60.4	65.5	67.6
Participants' contributions	0	0	'
Plan amendments	-1	0	'
Actuarial loss (gain)	-81.9	166.5	'
Curtailments	0	31.4	'
Gross benefits paid	-90.4	-107.2	'
Benefit Obligation at December 31	1,410.20	1,508.50	1,330.60
OPEB [Member]	'	'	'
Change in Benefit Obligation	'	'	'
Benefit Obligation at January 1	381.2	389.7	'
Service cost	10	10.3	10.4
Interest cost	15.6	20.3	20.8
Participants' contributions	8.9	9.6	'
Plan amendments	0	0.5	'
Actuarial loss (gain)	-27.7	-23.8	'
Curtailments	0	0	'
Gross benefits paid	-26.3	-26.3	'
Federal subsidy on benefits paid	1	0.9	'
Benefit Obligation at December 31	$362.70	$381.20	$389.70

Benefits_Details_1

Benefits (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Amounts recognized in Consolidated Balance Sheets	'	'	'
Other long-term liabilities	$173,200,000	$244,000,000	'
Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Accumulated Benefit Obligation	1,409,500,000	1,507,100,000	'
Defined Benefit Plan, Benefit Obligation	1,410,200,000	1,508,500,000	1,330,600,000
Change in Plan Assets	'	'	'
Fair Value at January 1	1,385,400,000	1,262,500,000	'
Actual earnings (loss) on plan assets	147,300,000	127,400,000	'
Employer contributions	8,700,000	102,700,000	'
Participants' contributions	0	0	'
Gross benefits paid	-90,400,000	-107,200,000	'
Fair Value at December 31	1,451,000,000	1,385,400,000	'
Amounts recognized in Consolidated Balance Sheets	'	'	'
Other deferred charges	138,700,000	0	'
Other long-term liabilities	97,900,000	123,100,000	'
Net Liability	40,800,000	-123,100,000	'
Amounts not yet been recognized in net periodic benefit cost	'	'	'
Net actuarial loss	528,800,000	719,200,000	'
Prior service costs (credits)	8,800,000	12,200,000	'
Total	537,600,000	731,400,000	'
OPEB [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Benefit Obligation	362,700,000	381,200,000	389,700,000
Change in Plan Assets	'	'	'
Fair Value at January 1	285,400,000	255,400,000	'
Actual earnings (loss) on plan assets	45,500,000	29,000,000	'
Employer contributions	14,100,000	17,700,000	48,400,000
Participants' contributions	8,900,000	9,600,000	'
Gross benefits paid	-26,300,000	-26,300,000	'
Fair Value at December 31	327,600,000	285,400,000	255,400,000
Amounts recognized in Consolidated Balance Sheets	'	'	'
Other deferred charges	40,200,000	25,100,000	'
Other long-term liabilities	75,300,000	120,900,000	'
Net Liability	-35,100,000	-95,800,000	'
Amounts not yet been recognized in net periodic benefit cost	'	'	'
Net actuarial loss	9,800,000	65,300,000	'
Prior service costs (credits)	-1,700,000	-3,700,000	'
Total	$8,100,000	$61,600,000	'

Benefits_Details_2

Benefits (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Matching contributions under Savings Plans	$14,200,000	$13,800,000	$14,100,000
A one-percentage-point change in assumed health care cost trend rates effects	'	'	'
1% Increase, in assumed health care cost trend rates, Effect on, Post-retirement benefit obligation	26,400,000	'	'
1% Decrease, in assumed health care cost trend rates, Effect on, Post-retirement benefit obligation	-22,300,000	'	'
1% Increase, in assumed health care cost trend rates, Effect on, Total of service and interest cost components	3,200,000	'	'
1% Decrease, in assumed health care cost trend rates, Effect on, Total of service and interest cost components	-2,600,000	'	'
Benefits (Textuals) [Abstract]	'	'	'
Health care cost trend rate up to specified age	'65	'	'
Health care cost trend rate post specified age	'65	'	'
Current pension plan target asset allocation in equity investments	45.00%	'	'
Current pension plan target asset allocation in fixed income investments	55.00%	'	'
Other Post-Retirement Employee Benefits target asset allocation in equity investments	60.00%	'	'
Other Post-Retirement Employee Benefits target asset allocation in fixed income investments	40.00%	'	'
Matching contributions under Savings Plans	14,200,000	13,800,000	14,100,000
Postemployment benefits liability	4,200,000	4,000,000	'
Pension, Qualified [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Funded Status of Plan	138,700,000	-20,900,000	'
Pension, Non-Qualified [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Funded Status of Plan	-97,900,000	-102,200,000	'
Pension Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Benefit Obligation	1,410,200,000	1,508,500,000	1,330,600,000
Defined Benefit Plan, Amortization of Previously Unrecognized Benefit Costs	38,700,000	'	'
Net Periodic Benefit Cost	'	'	'
Service cost	14,600,000	21,700,000	15,900,000
Interest cost	60,400,000	65,500,000	67,600,000
Expected return on plan assets	-95,800,000	-89,600,000	-82,100,000
Amortization of:	'	'	'
Transition obligation	0	0	0
Prior service cost (credit)	2,300,000	2,200,000	2,200,000
Actuarial loss	54,500,000	41,000,000	34,000,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	2,500,000	0	0
Curtailment (gain)	0	400,000	0
Net Periodic Benefit Cost	38,500,000	41,200,000	37,600,000
Weighted-Average assumptions used to determine benefit obligations as of Dec. 31	'	'	'
Discount rate	5.00%	4.10%	5.05%
Rate of compensation increase	4.00%	4.00%	4.00%
Weighted-Average assumptions used to determine net cost for year ended Dec. 31	'	'	'
Discount rate	4.10%	5.05%	5.60%
Expected return on plan assets	7.25%	7.25%	7.25%
Rate of compensation increase	4.00%	4.00%	4.00%
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	1,451,000,000	1,385,400,000	1,262,500,000
Employer contributions to defined benefit plan	'	'	'
Employer contributions	8,700,000	102,700,000	'
Expected benefit payments in future	'	'	'
2012	103,900,000	'	'
2013	98,600,000	'	'
2014	100,300,000	'	'
2015	100,900,000	'	'
2016	100,200,000	'	'
2017-2021	495,600,000	'	'
Pension Plans [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	873,200,000	763,100,000	'
Pension Plans [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	577,800,000	622,300,000	'
Pension Plans [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | Cash And Cash Equivalents [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	21,000,000	13,700,000	'
Pension Plans [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	21,000,000	13,700,000	'
Pension Plans [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | U.S. Equity [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	519,500,000	466,300,000	'
Pension Plans [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	519,500,000	466,300,000	'
Pension Plans [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | International Equity [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	181,900,000	165,100,000	'
Pension Plans [Member] | International Equity [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	146,200,000	134,700,000	'
Pension Plans [Member] | International Equity [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	35,700,000	30,400,000	'
Pension Plans [Member] | International Equity [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | U.S. Bonds [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	613,600,000	614,300,000	'
Pension Plans [Member] | U.S. Bonds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	108,400,000	67,700,000	'
Pension Plans [Member] | U.S. Bonds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	505,200,000	546,600,000	'
Pension Plans [Member] | U.S. Bonds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension Plans [Member] | International Bonds [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	115,000,000	126,000,000	'
Pension Plans [Member] | International Bonds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	78,100,000	80,700,000	'
Pension Plans [Member] | International Bonds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	36,900,000	45,300,000	'
Pension Plans [Member] | International Bonds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Benefit Obligation	362,700,000	381,200,000	389,700,000
Defined Benefit Plan, Amortization of Previously Unrecognized Benefit Costs	-900,000	'	'
Net Periodic Benefit Cost	'	'	'
Service cost	10,000,000	10,300,000	10,400,000
Interest cost	15,600,000	20,300,000	20,800,000
Expected return on plan assets	-21,300,000	-19,000,000	-16,900,000
Amortization of:	'	'	'
Transition obligation	0	300,000	300,000
Prior service cost (credit)	-2,000,000	-1,900,000	-1,900,000
Actuarial loss	3,700,000	7,300,000	6,200,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	0	0	0
Curtailment (gain)	0	0	0
Net Periodic Benefit Cost	6,000,000	17,300,000	18,900,000
Weighted-Average assumptions used to determine benefit obligations as of Dec. 31	'	'	'
Discount rate	4.95%	4.15%	5.20%
Weighted-Average assumptions used to determine net cost for year ended Dec. 31	'	'	'
Discount rate	4.15%	5.20%	5.70%
Expected return on plan assets	7.50%	7.50%	7.50%
Assumed health care cost trend rates as of Dec. 31	'	'	'
Health care cost trend rate assumed for next year, Pre 65	0.075	0.075	0.08
Health care cost trend rate assumed for next year, Post 65	0.075	0.075	0.12
Rate that the cost trend rate gradually adjusts to	0.05	0.05	0.05
Year that the rate reaches the rate it is assumed to remain at (Pre 65 / Post 65)	'2021/2021	'2017/2017	'2017/2017
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	327,600,000	285,400,000	255,400,000
Employer contributions to defined benefit plan	'	'	'
Employer contributions	14,100,000	17,700,000	48,400,000
Expected benefit payments in future	'	'	'
2012	24,200,000	'	'
2013	21,600,000	'	'
2014	22,000,000	'	'
2015	22,600,000	'	'
2016	23,400,000	'	'
2017-2021	119,700,000	'	'
OPEB [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	222,700,000	187,900,000	'
OPEB [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	104,900,000	97,500,000	'
OPEB [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | Cash And Cash Equivalents [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	2,600,000	1,700,000	'
OPEB [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	2,600,000	1,700,000	'
OPEB [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | U.S. Equity [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	148,000,000	125,900,000	'
OPEB [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	148,000,000	125,900,000	'
OPEB [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | U.S. Equity [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | International Equity [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	49,700,000	42,100,000	'
OPEB [Member] | International Equity [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	46,900,000	39,900,000	'
OPEB [Member] | International Equity [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	2,800,000	2,200,000	'
OPEB [Member] | International Equity [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | U.S. Bonds [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	104,700,000	94,900,000	'
OPEB [Member] | U.S. Bonds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	8,400,000	5,000,000	'
OPEB [Member] | U.S. Bonds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	96,300,000	89,900,000	'
OPEB [Member] | U.S. Bonds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
OPEB [Member] | International Bonds [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	22,600,000	20,800,000	'
OPEB [Member] | International Bonds [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	16,800,000	15,400,000	'
OPEB [Member] | International Bonds [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	5,800,000	5,400,000	'
OPEB [Member] | International Bonds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Summary of fair value of pension plan assets by asset category within the fair value hierarchy	'	'	'
Fair value of our pension plan assets	0	0	'
Pension, Qualified [Member] | Pension Plans [Member]	'	'	'
Employer contributions to defined benefit plan	'	'	'
Employer contributions	0	95,600,000	236,400,000
Pension, Non-Qualified [Member] | Pension Plans [Member]	'	'	'
Employer contributions to defined benefit plan	'	'	'
Employer contributions	$8,700,000	$7,100,000	$6,500,000

Segment_Reporting_Details

Segment Reporting (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Financial information of reportable operating segments	'		'		'
Operating Revenues	$4,519	[1]	$4,246.40	[1]	$4,486.40	[1]
Depreciation and Amortization	388.1		364.2		330.2
Operating Income (Loss)	1,080.10		1,000.30		887.3
Equity in Earnings of Unconsolidated Affiliates	68.4		65.5		61.6
Interest Expense, net	252.1		248.2		235.8
Income Tax Expense (Benefit)	337.9		306.3		263.9
Income from Discontinued Operations, Net of Tax	0		0		13.4
Net Income (Loss)	577.4		546.3		526.2
Capital Expenditures	687.4		707		830.8
Total Assets	-14,769.40	[2]	-14,285	[2]	-13,862.10	[2]
Utility Energy [Member]	'		'		'
Financial information of reportable operating segments	'		'		'
Operating Revenues	4,462	[1]	4,190.80	[1]	4,431.50	[1]
Depreciation and Amortization	320.2		296.4		257
Operating Income (Loss)	719.4		647.7		544.8
Equity in Earnings of Unconsolidated Affiliates	68.5		65.7		62.5
Interest Expense, net	136.2		129.4		110
Income Tax Expense (Benefit)	243.6		214.9		182.7
Income from Discontinued Operations, Net of Tax	'		'		0
Net Income (Loss)	425.1		400.6		376.3
Capital Expenditures	657.9		697.3		792.2
Total Assets	-14,460.40	[2]	-13,988.10	[2]	-13,433.50	[2]
Non-Utility Energy [Member]	'		'		'
Financial information of reportable operating segments	'		'		'
Operating Revenues	446.7	[1]	439.9	[1]	435.1	[1]
Depreciation and Amortization	67.1		67.1		72.5
Operating Income (Loss)	367.1		358.8		348.9
Equity in Earnings of Unconsolidated Affiliates	0		0		0
Interest Expense, net	65.7		66.7		66.7
Income Tax Expense (Benefit)	120.2		116.6		112.8
Income from Discontinued Operations, Net of Tax	'		'		0
Net Income (Loss)	181.6		175.9		169.8
Capital Expenditures	26.1		5.5		31.2
Total Assets	-2,846.50	[2]	-2,903.50	[2]	-2,949	[2]
Corporate and Other [Member]	'		'		'
Financial information of reportable operating segments	'		'		'
Operating Revenues	1.3	[1],[3]	1.2	[1],[3]	0.9	[1],[3]
Depreciation and Amortization	0.8	[3]	0.7	[3]	0.7	[3]
Operating Income (Loss)	-6.4	[3]	-6.2	[3]	-6.4	[3]
Equity in Earnings of Unconsolidated Affiliates	-0.1	[3]	-0.2	[3]	-0.9	[3]
Interest Expense, net	50.8	[3]	52.5	[3]	59.5	[3]
Income Tax Expense (Benefit)	-25.9	[3]	-25.2	[3]	-31.6	[3]
Income from Discontinued Operations, Net of Tax	'		'		13.4	[3]
Net Income (Loss)	577.2	[3]	546.1	[3]	525.9	[3]
Capital Expenditures	3.4	[3]	4.2	[3]	7.4	[3]
Total Assets	-4,719.50	[2],[3]	-4,431.40	[2],[3]	-4,694.80	[2],[3]
Reconciling Items [Member]	'		'		'
Financial information of reportable operating segments	'		'		'
Operating Revenues	-391	[1]	-385.5	[1]	-381.1	[1]
Depreciation and Amortization	0		0		0
Operating Income (Loss)	0		0		0
Equity in Earnings of Unconsolidated Affiliates	0		0		0
Interest Expense, net	-0.6		-0.4		-0.4
Income Tax Expense (Benefit)	0		0		0
Income from Discontinued Operations, Net of Tax	'		'		0
Net Income (Loss)	-606.5		-576.3		-545.8
Capital Expenditures	0		0		0
Total Assets	7,257	[2]	7,038	[2]	7,215.20	[2]
Elimination [Member]	'		'		'
Financial information of reportable operating segments	'		'		'
Total Assets	$2,231.20		$2,286.70		$2,369
[1]	An elimination for intersegment revenues is included in Operating Revenues. This elimination is primarily between We Power and Wisconsin Electric.
[2]	An elimination of $2,231.2 million, $2,286.7 million and $2,369.0 million is included in Total Assets as of December 31, 2013, 2012 and 2011, respectively, for all PTF-related activity between We Power and Wisconsin Electric.
[3]	Corporate & Other includes all other non-utility activities, primarily non-utility real estate investment and development by Wispark as well as interest on corporate debt.

Related_Parties_Details

Related Parties (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]	'	'	'
Income (Loss) from Equity Method Investments	$68.40	$65.50	$61.60
American Transmission Company [Member]	'	'	'
Provided and received services from the associated companies	'	'	'
Services Received, -ATC	234.2	222.7	219.2
Receivable and payable balances with ATC	'	'	'
Services Received, -ATC	19.5	18.6	'
Related Parties (Textuals) [Abstract]	'	'	'
Equity interest in ATC	26.20%	'	'
Services [Member] | American Transmission Company [Member]	'	'	'
Provided and received services from the associated companies	'	'	'
Services Provided, -ATC	9	8.2	10.8
Receivable and payable balances with ATC	'	'	'
Services Provided, -ATC	0.6	0.5	'
Transmission Affiliate [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Income (Loss) from Equity Method Investments	68.5	65.7	62.5
Distributions from transmission affiliate	$54.50	$52.60	$49.70

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Future minimum payments for the next five years and thereafter for our operating lease contracts	'	'	'
2014	$3.90	'	'
2015	3.9	'	'
2016	3.7	'	'
2017	3.1	'	'
2018	3.2	'	'
Thereafter	22.7	'	'
Total	40.5	'	'
Manufactured Gas Plant Sites [Member]	'	'	'
Commitment and Contingencies (Textuals) [Abstract]	'	'	'
Reserves related to future remediation costs	36.9	38.2	'
Commitments and Contingencies (Textuals) [Abstract]	'	'	'
Estimated future detailed site investigation and remediation costs, minimum	19	'	'
Estimated Future detailed site investigation and remediation costs, maximum	56	'	'
Period for future costs of detailed site investigation and remediation costs	'over the next ten years	'	'
Period to recover remediation cost of manufactured gas plant sites	'5 years	'	'
Coal combustion product landfill sites [Member]	'	'	'
Commitment and Contingencies (Textuals) [Abstract]	'	'	'
Expense related to environmental remediation	0.1	0.3	0.2
Reserves related to landfill sites	0	'	'
Commitments and Contingencies (Textuals) [Abstract]	'	'	'
Expense related to environmental remediation	0.1	0.3	0.2
Minimum [Member]	'	'	'
Commitments and Contingencies [Line Items]	'	'	'
VAPP Conversion Cost	65	'	'
Maximum [Member]	'	'	'
Commitments and Contingencies [Line Items]	'	'	'
VAPP Conversion Cost	$70	'	'

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Cash Flow Information (Textuals)	'	'	'
Interest paid, net of amounts capitalized	$250.40	$241.20	$234
Net refunds from income taxes	39.6	107	109.1
Accounts payable related to capital expenditures	4.7	15.7	16.7
Deferred Revenue, Revenue Recognized	56.5	54.9	54.4
Grants Receivable, Current	82.6	'	'
Revenue from Grants	$48	$0	$0

Condensed_Parent_Company_Finan

Condensed Parent Company Financial Statements (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Parent Company Income Statement	'	'	'
Other Income, Net	$18.80	$34.80	$62.70
Interest Expense, net	252.1	248.2	235.8
Income (Loss) from Continuing Operations Before Income Taxes	915.3	852.6	776.7
Income Tax Benefit	-337.9	-306.3	-263.9
Income from Continuing Operations	577.4	546.3	512.8
Income from Discontinued Operations, Net of Tax	0	0	13.4
Net Income	577.4	546.3	526.2
Subsidiaries [Member]	'	'	'
Condensed Parent Company Income Statement	'	'	'
Income from Continuing Operations	607.8	577.6	545.9
Income from Discontinued Operations, Net of Tax	0	0	13.4
Wisconsin Energy Corporation [Member]	'	'	'
Condensed Parent Company Income Statement	'	'	'
Other Income, Net	3.1	3.2	2.7
Corporate Expense	5.5	4.8	4.8
Interest Expense, net	54.4	55.7	61.8
Income (Loss) from Continuing Operations Before Income Taxes	-56.8	-57.3	-63.9
Income Tax Benefit	26.4	26	30.8
Income from Continuing Operations	-30.4	-31.3	-33.1
Net Income	$577.40	$546.30	$526.20

Condensed_Parent_Company_Finan1

Condensed Parent Company Financial Statements (Details 1) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
In Millions, unless otherwise specified
Current Assets	'		'		'		'
Cash and cash equivalents	$26		$35.60		$14.10		$24.50
Prepaid taxes and other	145.7		145.5		'		'
Total Current Assets	1,551.10		1,272.60		'		'
Property and Investments	'		'		'		'
Investment in subsidiary companies	402.7		378.3		'		'
Other	322.5		204.2		'		'
Total Deferred Charges and Other Assets	1,872.90		2,026.40		'		'
Total Assets	14,769.40	[1]	14,285	[1]	13,862.10	[1]	'
Current Liabilities	'		'		'		'
Short-term debt	537.4		394.6		'		'
Other	177.3		165.4		'		'
Total Current Liabilities	1,496.40		1,441.40		'		'
Long-term debt	4,363.20		4,453.80		'		'
Other Long-term liabilities	295.9		285.2		'		'
Stockholder's equity	4,233		4,135.10		3,963.30		3,802.10
Total Capitalization and Liabilities	14,769.40		14,285		'		'
Wisconsin Energy Corporation [Member]	'		'		'		'
Current Assets	'		'		'		'
Cash and cash equivalents	0.3		0.9		0.5		0.6
Accounts and notes receivable from associated companies	37.4		32.9		'		'
Prepaid taxes and other	297.6		176.3		'		'
Total Current Assets	335.3		210.1		'		'
Property and Investments	'		'		'		'
Investment in subsidiary companies	4,761.80		4,662.30		'		'
Other	1.8		2.1		'		'
Total Property and Investments	4,763.60		4,664.40		'		'
Total Deferred Charges and Other Assets	143.2		331.4		'		'
Total Assets	5,242.10		5,205.90		'		'
Current Liabilities	'		'		'		'
Short-term debt	72		67		'		'
Notes payable due associated companies	113.8		140.6		'		'
Other	11.8		34.7		'		'
Total Current Liabilities	197.6		242.3		'		'
Long-term debt	695		694.3		'		'
Other Long-term liabilities	116.5		134.2		'		'
Stockholder's equity	4,233		4,135.10		'		'
Total Capitalization and Liabilities	$5,242.10		$5,205.90		'		'
[1]	An elimination of $2,231.2 million, $2,286.7 million and $2,369.0 million is included in Total Assets as of December 31, 2013, 2012 and 2011, respectively, for all PTF-related activity between We Power and Wisconsin Electric.

Condensed_Parent_Company_Finan2

Condensed Parent Company Financial Statements (Details 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Activities	'	'	'
Net income	$577.40	$546.30	$526.20
Reconciliation to cash	'	'	'
Deferred income taxes, net	313.8	294.4	434.8
Accrued income taxes, net	36.6	116.9	-87.4
Other current assets	2.8	12.1	-20.5
Other current liabilities	7.2	-14.9	44.1
Accounts receivable and accrued revenues	-162.9	38.3	30.1
Other, net	49.2	-164	-23.5
Cash Provided by Operating Activities	1,231	1,173.90	993.4
Investing Activities	'	'	'
Proceeds from asset sales	2.5	8.7	41.5
Capital contributions to associated companies	-10.5	-15.7	-6.6
Cash Used in Investing Activities	-745.8	-729.6	-892.5
Financing Activities	'	'	'
Exercise of stock options	48.5	49.8	54.4
Purchase of common stock	-223.4	-153.2	-193.9
Dividends paid on common stock	-328.9	-276.3	-242
Issuance of long-term debt	251	251.8	720
Retirement and repurchase of long-term debt	-397.2	-20.3	-466.6
Change in short-term debt	142.8	-275.3	12
Other, net	12.4	0.7	4.8
Cash Used in Financing Activities	-494.8	-422.8	-111.3
Change in Cash and Cash Equivalents	-9.6	21.5	-10.4
Cash and Cash Equivalents at Beginning of Year	35.6	14.1	24.5
Cash and Cash Equivalents at End of Year	26	35.6	14.1
Wisconsin Energy Corporation [Member]	'	'	'
Operating Activities	'	'	'
Net income	577.4	546.3	526.2
Reconciliation to cash	'	'	'
Equity in susidiaries' earnings	-607.8	-577.6	-545.9
Dividends and distributions from subsidiaries	720.4	842.3	995.5
Deferred income taxes, net	-7.8	104.4	-350.9
Accrued income taxes, net	66.8	-457.9	363.4
Other current assets	-0.1	0.2	-0.1
Other current liabilities	-22.9	-6.7	8.9
Accounts receivable and accrued revenues	-2.7	22.5	-18.7
Other, net	-21.6	-8.1	-10.2
Cash Provided by Operating Activities	701.7	465.4	968.2
Investing Activities	'	'	'
Capital contributions to associated companies	-195.3	-21.5	-36.5
Capitalized interest and other	4	12.6	2.4
Cash Used in Investing Activities	-191.3	-8.9	-34.1
Financing Activities	'	'	'
Exercise of stock options	48.5	49.8	54.4
Purchase of common stock	-223.4	-153.9	-193.9
Dividends paid on common stock	-328.9	-276.3	-242
Retirement and repurchase of long-term debt	0	0	-450
Change in short-term debt	5	-79.5	-116.5
Change in notes payable due associated companies	-26.8	3.8	3.9
Other, net	14.6	0	9.9
Cash Used in Financing Activities	-511	-456.1	-934.2
Change in Cash and Cash Equivalents	-0.6	0.4	-0.1
Cash and Cash Equivalents at Beginning of Year	0.9	0.5	0.6
Cash and Cash Equivalents at End of Year	$0.30	$0.90	$0.50

Condensed_Parent_Company_Finan3

Condensed Parent Company Financial Statements (Details 3) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Parent Company long-term debt outstanding	'
Next year	$322.40
Year 2	399.5
Year 3	27.4
Year 4	29.5
Year 5	281.1
Thereafter	3,566.80
Total	4,626.70
Wisconsin Energy Corporation [Member]	'
Parent Company long-term debt outstanding	'
Next year	0
Year 2	0
Year 3	0
Year 4	0
Year 5	0
Thereafter	700
Total	$700

Condensed_Parent_Company_Finan4

Condensed Parent Company Financial Statements (Details 4) (Wisconsin Energy Corporation [Member], USD $)	Dec. 31, 2013
Various guarantees to provide financial and performance assurance to third parties on behalf of affiliates	'
Guarantees, Maximum Potential Future Payments	$59,600,000
Guarantees, Outstanding	3,800,000
Liability	0
Letters of Credit [Member]	'
Various guarantees to provide financial and performance assurance to third parties on behalf of affiliates	'
Guarantees, Maximum Potential Future Payments	100,000
Guarantees, Outstanding	100,000
Liability	0
Utility Energy [Member]	'
Various guarantees to provide financial and performance assurance to third parties on behalf of affiliates	'
Guarantees, Maximum Potential Future Payments	3,800,000
Guarantees, Outstanding	3,800,000
Liability	0
Non-Utility Energy [Member]	'
Various guarantees to provide financial and performance assurance to third parties on behalf of affiliates	'
Guarantees, Maximum Potential Future Payments	55,500,000
Guarantees, Outstanding	0
Liability	0
Corporate and Other [Member]	'
Various guarantees to provide financial and performance assurance to third parties on behalf of affiliates	'
Guarantees, Maximum Potential Future Payments	300,000
Guarantees, Outstanding	0
Liability	$0

Condensed_Parent_Company_Finan5

Condensed Parent Company Financial Statements (Details 5) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Parent Company Financial Statements (Textuals) [Abstract]	'	'	'
Issuance of new notes and the proceeds used to repay short-term debt	$397.20	$20.30	$466.60
Issuance of Junior Notes	251	251.8	720
Restriction under RCC	'The RCC provides that we may not redeem, defease or purchase and our subsidiaries may not purchase any Junior Notes on or before May 15, 2037, unless, subject to certain limitations described in the RCC, during the 180 days prior to the date of redemption, defeasance or purchase, we have received a specified amount of proceeds from the sale of qualifying securities.	'	'
Interest paid, net of amounts capitalized	250.4	241.2	234
Net refunds from income taxes	39.6	107	109.1
Wisconsin Energy Corporation [Member]	'	'	'
Condensed Parent Company Financial Statements (Textuals) [Abstract]	'	'	'
Long-term notes outstanding of WECC	50	'	'
Issuance of new notes and the proceeds used to repay short-term debt	0	0	450
Minimum Total Funded Debt to Capitalization Ratio, As a Percent	70.00%	'	'
Interest paid, net of amounts capitalized	44.4	45.2	57.7
Net refunds from income taxes	86.1	128.2	114.6
Wisconsin Electric and Wisconsin Gas [Member]	'	'	'
Condensed Parent Company Financial Statements (Textuals) [Abstract]	'	'	'
Dividends and distributions from subsidiaries	373	'	'
We Power [Member]	'	'	'
Condensed Parent Company Financial Statements (Textuals) [Abstract]	'	'	'
Dividends and distributions from subsidiaries	$347.40	'	'
Notes (unsecured), 6.20% due 2033 [Member]	'	'	'
Condensed Parent Company Financial Statements (Textuals) [Abstract]	'	'	'
Debt instrument interest rate stated percentage rate	6.20%	6.20%	'
Junior Notes (unsecured), 6.25% due 2067 [Member]	'	'	'
Condensed Parent Company Financial Statements (Textuals) [Abstract]	'	'	'
Debt instrument interest rate stated percentage rate	6.25%	6.25%	'

Condensed_Parent_Company_Finan6

Condensed Parent Company Financial Statements (Details 6) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Instruments	'	'
Long-term debt including current portion, carrying value	$4,626.70	$4,772.90
Long-term debt including current portion, fair value	4,911.80	5,447.30
Carrying Amount [Member] | Wisconsin Energy Corporation [Member]	'	'
Financial Instruments	'	'
Long-term debt including current portion, carrying value	700	700
Fair Value [Member] | Wisconsin Energy Corporation [Member]	'	'
Financial Instruments	'	'
Long-term debt including current portion, fair value	$749.40	$805.90

Schedule_I_Condensed_Parent_Co1

Schedule I -- Condensed Parent Company Financial Statements Condensed Parent Company Financial Statements (Details 7) (Details) (Parent Company [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Parent Company [Member]	'
Subsequent Event [Line Items]	'
Special Dividend Paid from Wisconsin Electric to Parent Company	$50

Valuation_and_Qualifying_Accou

Valuation and Qualifying Accounts (Details) (Allowance for Doubtful Accounts [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts [Member]	'	'	'
Valuation and Qualifying Accounts	'	'	'
Balance at Beginning of the Period	$58	$61.70	$58.10
Expense	49.4	47.7	85.8
Deferral	0.4	-4	-35.9
Net Write-offs	-46.8	-47.4	-46.3
Balance at End of the Period	$61	$58	$61.70

Preferred_Stock_Details

Preferred Stock (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]	'	'
Preferred Stock, Value, Issued	$30.40	$30.40
Six Per Cent. Preferred Stock [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	45,000	'
Preferred Stock, Shares Outstanding	44,498	'
Preferred Stock, Redemption Price Per Share	$0	'
Preferred Stock, Value, Issued	4.4	'
Serial preferred stock, $100 par value; authorized 2,286,500 shares [Member] [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	2,286,500	'
Serial preferred stock, 3.60% Series Redeemable [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Outstanding	260,000	'
Preferred Stock, Redemption Price Per Share	$101	'
Preferred Stock, Value, Issued	26	'
Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	5,000,000	'
Preferred Stock, Shares Outstanding	0	'
Preferred Stock, Redemption Price Per Share	$0	'
Preferred Stock, Value, Issued	0	'
Wisconsin Electric [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Value, Issued	30.4	30.4
Wisconsin Electric [Member] | Six Per Cent. Preferred Stock [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	'	45,000
Preferred Stock, Dividend Rate, Percentage	6.00%	6.00%
Preferred Stock, Par or Stated Value Per Share	$100	$100
Preferred Stock, Shares Outstanding	'	44,498
Preferred Stock, Redemption Price Per Share	'	$0
Preferred Stock, Value, Issued	'	4.4
Wisconsin Electric [Member] | Serial preferred stock, $100 par value; authorized 2,286,500 shares [Member] [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	'	2,286,500
Preferred Stock, Par or Stated Value Per Share	$100	$100
Wisconsin Electric [Member] | Serial preferred stock, 3.60% Series Redeemable [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Dividend Rate, Percentage	3.60%	3.60%
Preferred Stock, Par or Stated Value Per Share	$100	$100
Preferred Stock, Shares Outstanding	'	260,000
Preferred Stock, Redemption Price Per Share	'	$101
Preferred Stock, Value, Issued	'	26
Wisconsin Electric [Member] | Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	'	5,000,000
Preferred Stock, Par or Stated Value Per Share	$0	$0
Preferred Stock, Shares Outstanding	'	0
Preferred Stock, Redemption Price Per Share	'	$0
Preferred Stock, Value, Issued	'	0
Wisconsin Energy Corporation [Member]	'	'
Class of Stock [Line Items]	'	'
Preferred Stock, Shares Authorized	15,000,000	15,000,000
Preferred Stock, Par or Stated Value Per Share	$0.01	$0.01
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Redemption Price Per Share	$0	$0
Preferred Stock, Value, Issued	$0	$0