Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Estimated Minimum Purchases Under Fuel Contracts

The estimated minimum purchases for SPS under these contracts as of Dec. 31, 2014, are as follows:

(Millions of Dollars)	Coal		Natural gas supply		Natural gas storage and transportation
2015	$	258.0	$	3.3	$	31.0
2016	225.1		—		30.8
2017	114.9		—		22.1
2018	—		—		20.6
2019	—		—		21.5
Thereafter	—		—		95.9
Total	$	598.0	$	3.3	$	221.9

Estimated Future Payments for Capacity Pursuant to Purchased Power Agreements

At Dec. 31, 2014, the estimated future payments for capacity that SPS is obligated to purchase pursuant to these executory contracts, subject to availability, are as follows:

(Millions of Dollars)
2015	$	56.6
2016	57.1
2017	58.3
2018	59.6
2019	19.5
Thereafter	36.1
Total (a)	$	287.2

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

Future Commitments Under Operating Leases

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

(Millions of Dollars)	Operating Leases		PPA (a) (b) Operating Leases		Total Operating Leases
2015	$	3.3	$	52.0	$	55.3
2016	3.4		49.0		52.4
2017	2.4		49.0		51.4
2018	2.0		49.0		51.0
2019	1.9		49.0		50.9
Thereafter	11.4		671.8		683.2

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

^(b)  PPA operating leases contractually expire through 2033.

Asset Retirement Obligations

A reconciliation of SPS’ AROs for the years ended Dec. 31, 2014 and 2013 is as follows:

(Thousands of Dollars)	Beginning Balance Jan. 1, 2014		Liabilities Recognized		Accretion		Cash Flow Revisions		Ending Balance Dec. 31, 2014 (a)
Electric plant
Steam production asbestos	$	11,608	$	—	$	795	$	4,554	$	16,957
Steam production ash containment	809		—		51		749		1,609
Electric distribution	6,104		—		223		—		6,327
Other	854		136		31		117		1,138
Total liability	$	19,375	$	136	$	1,100	$	5,420	$	26,031

^(a)  There were no ARO liabilities settled during the year ended Dec. 31, 2014.

(Thousands of Dollars)	Beginning Balance Jan. 1, 2013		Liabilities Settled			Accretion		Cash Flow Revisions			Ending Balance Dec. 31, 2013 (a)
Electric plant
Steam production asbestos	$	10,979	$	(118	)	$	747	$	—		$	11,608
Steam production ash containment	764		—			48		(3		)	809
Electric distribution	5,303		—			171		630			6,104
Other	561		—			42		251			854
Total liability	$	17,607	$	(118	)	$	1,008	$	878		$	19,375

^(a)  There were no new ARO liabilities recognized during the year ended Dec. 31, 2013.