Fair Value of Financial Assets and Liabilities (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Gross Notional Amounts of Commodity Forwards and Options

The following table details the gross notional amounts of commodity options at June 30, 2015 and Dec. 31, 2014:

(Amounts in Thousands)(a)(b)	June 30, 2015	Dec. 31, 2014
Million British thermal units of natural gas	1,223	18

^(a)  Amounts are not reflective of net positions in the underlying commodities.

^(b)  Notional amounts for options are included on a gross basis, but are weighted for the probability of exercise.

Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level

Recurring Fair Value Measurements — The following tables present for each of the fair value hierarchy levels, NSP-Wisconsin’s derivative assets and liabilities measured at fair value on a recurring basis:

	June 30, 2015
	Fair Value						Fair Value Total		Counterparty Netting(a)			Total(b)
(Thousands of Dollars)	Level 1		Level 2		Level 3
Current derivative assets
Natural gas commodity	$	—	$	3	$	—	$	3	$	(3	)	$	—
Total current derivative assets	$	—	$	3	$	—	$	3	$	(3	)	$	—
Current derivative liabilities
Natural gas commodity	$	—	$	48	$	—	$	48	$	(3	)	$	45
Total current derivative liabilities	$	—	$	48	$	—	$	48	$	(3	)	$	45

	Dec. 31, 2014
	Fair Value						Fair Value Total		Counterparty Netting(a)		Total(b)
(Thousands of Dollars)	Level 1		Level 2		Level 3
Current derivative assets
Natural gas commodity	$	—	$	52	$	—	$	52	$	—	$	52

^(a)  NSP-Wisconsin nets derivative instruments and related collateral in its consolidated balance sheet when supported by a legally enforceable master netting agreement, and all derivative instruments and related collateral amounts were subject to master netting agreements at Dec. 31, 2014.  The counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

^(b)  Included in other current liabilities balance of $22.2 million at June 30, 2015 and prepayments and other assets balance of $6.9 million at Dec. 31, 2014, in the consolidated balance sheets.

Carrying Amount and Fair Value of Long-term Debt

As of June 30, 2015 and Dec. 31, 2014, other financial instruments for which the carrying amount did not equal fair value were as follows:

	June 30, 2015				Dec. 31, 2014
(Thousands of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt, including current portion	$	667,523	$	730,460	$	568,291	$	670,665