Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2013

Commitments and Contingencies Disclosure [Abstract]

Estimated Minimum Purchases Under Fuel Contracts [Abstract]

The estimated minimum purchases for PSCo under these contracts as of Dec. 31, 2013, were as follows:



(Millions of Dollars)	Coal		Natural gas supply		Natural gas storage and transportation
2014	$	330.3	$	384.3	$	137.2
2015	265.4		228.0		136.5
2016	232.2		225.6		77.1
2017	153.8		222.1		50.9
2018	42.5		278.4		50.8
Thereafter	424.7		1,211.1		854.4
Total	$	1,448.9	$	2,549.5	$	1,306.9

Schedule of Long-term Contracts for Purchase of Electric Power [Table Text Block]

Included in electric fuel and purchased power expenses for PPAs, accounted for as executory contracts, were payments for capacity of $72.7 million, $119.5 million and $178.8 million in 2013, 2012 and 2011, respectively. At Dec. 31, 2013, the estimated future payments for capacity and energy that PSCo is obligated to purchase pursuant to these executory contracts, subject to availability, were as follows:



(Millions of Dollars)	Capacity		Energy^(a)
2014	$	82.4	$	43.6
2015	82.6		36.8
2016	58.3		18.6
2017	35.2		3.1
2018	28.1		—
Thereafter	69.9		—
Total	$	356.5	$	102.1


^(a)	Excludes contingent energy payments for renewable energy PPAs.

Schedule of Capital Leased Assets [Table Text Block]

PSCo records amortization for its capital leases as cost of natural gas sold and transported on the consolidated statements of income. Total amortization expenses under capital lease assets were approximately $6.3 million, $5.7 million, and $3.2 million for 2013, 2012 and 2011, respectively. Following is a summary of property held under capital leases:



(Millions of Dollars)	Dec. 31, 2013			Dec. 31, 2012
Storage, leaseholds and rights	$	200.5		$	200.5
Gas pipeline	20.7			20.7
Property held under capital lease	221.2			221.2
Accumulated depreciation	(41.8		)	(35.5		)
Total property held under capital leases, net	$	179.4		$	185.7

Schedule Of Future Minimum Rental Payments For Operating And Capital Leases [Table Text Block]

Included in the future commitments under operating leases are estimated future payments under PPAs that have been accounted for as operating leases in accordance with the applicable accounting guidance. Future commitments under operating and capital leases are:



(Millions of Dollars)	Operating Leases		PPA Operating Leases ^{(a) (b)}		Total Operating Leases		Capital Leases
2014	$	14.8	$	94.8	$	109.6	$	30.6
2015	14.6		95.3		109.9		30.5
2016	11.7		84.0		95.7		29.3
2017	6.9		78.7		85.6		25.6
2018	6.6		79.3		85.9		25.2
Thereafter	48.0		548.6		596.6		538.2
Total minimum obligation							679.4
Interest component of obligation							(500.0		)
Present value of minimum obligation							$	179.4


^(a)	Amounts do not include PPAs accounted for as executory contracts.


^(b)	PPA operating leases contractually expire through 2028.

Schedule of Asset Retirement Obligations [Table Text Block]

A reconciliation of PSCo’s AROs is shown in the tables below for the years ended Dec. 31, 2013 and 2012, respectively:



(Thousands of Dollars)	Beginning Balance Jan. 1, 2013		Liabilities Recognized		Liabilities Settled			Accretion		Revisions to Prior Estimates			Ending Balance Dec. 31, 2013
Electric plant
Steam and other production asbestos	$	19,734	$	—	$	(941	)	$	1,247	$	3,874		$	23,914
Steam and other production ash containment	12,919		—		—			684		15,631			29,234
Wind production	2,928		—		—			25		—			2,953
Electric distribution	6,392		—		—			178		(5,394		)	1,176
Other	627		—		—			60		330			1,017
Natural gas plant
Gas transmission and distribution	842		—		—			53		(107		)	788
Gas gathering	—		575		—			—		—			575
Common and other property
Common miscellaneous	309		—		—			29		403			741
Total liability	$	43,751	$	575	$	(941	)	$	2,276	$	14,737		$	60,398



(Thousands of Dollars)	Beginning Balance Jan. 1, 2012		Liabilities Recognized		Liabilities Settled			Accretion		Revisions to Prior Estimates			Ending Balance Dec. 31, 2012
Electric plant
Steam and other production asbestos	$	23,062	$	—	$	(9,372	)	$	1,536	$	4,508		$	19,734
Steam and other production ash containment	9,449		—		—			499		2,971			12,919
Wind production	—		2,928		—			—		—			2,928
Electric distribution	8,005		—		—			290		(1,903		)	6,392
Other	583		—		—			25		19			627
Natural gas plant
Gas transmission and distribution	810		—		—			48		(16		)	842
Common and other property
Common miscellaneous	298		—		—			11		—			309
Total liability	$	42,207	$	2,928	$	(9,372	)	$	2,409	$	5,579		$	43,751