Benefit Plans and Other Postretirement Benefits, Pension Plan Benefit Obligations, Cash Flows and Benefit Costs (Details) (Pension Plans, USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2014	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Accumulated Benefit Obligation at Dec. 31		$ 1,134,184,000		$ 1,178,447,000
Change in Projected Benefit Obligation [Roll Forward]
Obligation at Jan. 1	1,152,836,000	1,194,371,000		1,047,373,000
Service cost		25,206,000		22,719,000		17,726,000
Interest cost		46,160,000		51,192,000		52,234,000
Transfer from other plan		11,306,000		0
Plan amendments		0		626,000
Actuarial (gain) loss		(49,384,000)		138,259,000
Benefit payments		(74,823,000)		(65,798,000)
Obligation at Dec. 31		1,152,836,000		1,194,371,000		1,047,373,000
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at Jan. 1	1,067,057,000	1,055,308,000		969,207,000
Actual return (loss) on plan assets		30,684,000		110,113,000
Employer contributions		44,582,000		41,786,000
Transfer from other plan		11,306,000		0
Benefit payments		(74,823,000)		(65,798,000)
Fair value of plan assets at Dec. 31		1,067,057,000		1,055,308,000		969,207,000
Funded Status of Plans at Dec. 31 [Abstract]
Funded status		(85,779,000)	[1]	(139,063,000)	[1]
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost [Abstract]
Net loss		450,202,000		509,867,000
Prior service (credit) cost		(21,800,000)		(22,864,000)
Total		428,402,000		487,003,000
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates [Abstract]
Current regulatory assets		36,271,000		33,177,000
Noncurrent regulatory assets		392,131,000		453,826,000
Total		428,402,000		487,003,000
Significant Assumptions Used to Measure Benefit Obligations [Abstract]
Measurement date		2013-12-31		2012-12-31
Discount rate for year-end valuation (in hundredths)		4.75%		4.00%
Expected average long-term increase in compensation level (in hundredths)		3.75%		3.75%
Mortality table		RP 2000		RP 2000
Cash Flows [Abstract]
Total contributions to Xcel Energy's pension plans during the period	35,100,000	44,600,000		41,800,000		60,500,000
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		25,206,000		22,719,000		17,726,000
Interest cost		46,160,000		51,192,000		52,234,000
Expected return on plan assets		(63,821,000)		(65,302,000)		(67,946,000)
Amortization of prior service (credit) cost		(1,064,000)		228,000		222,000
Amortization of net loss		43,418,000		34,332,000		28,126,000
Net periodic benefit cost		49,899,000		43,169,000		30,362,000
Significant Assumptions Used to Measure Costs [Abstract]
Discount rate (in hundredths)		4.00%		5.00%		5.50%
Expected average long-term increase in compensation level (in hundredths)		3.75%		4.00%		4.00%
Expected average long-term rate of return on assets (in hundredths)		6.47%		6.65%		7.00%
Allocated costs for pension plans sponsored by Xcel Energy Inc.		11,600,000		9,600,000		6,800,000
Expected average long-term rate of return on assets for next fiscal year (in hundredths)		6.81%
Number of years fair market value of plan assets is adjusted using calculated value method (in years)		5 years
Annual adjustment rate used in calculated value method (in hundredths)		20.00%
Xcel Energy Inc.
Cash Flows [Abstract]
Total contributions to Xcel Energy's pension plans during the period	$ 130,000,000	$ 192,400,000		$ 198,100,000		$ 137,300,000
Number of pension plans to which contributions were made	3	4		4		3

[1] Amounts are recognized in noncurrent liabilities on PSCo’s consolidated balance sheets.