Fair Value (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Inputs, Liabilities, Quantitative Information [Line Items]

Fair Value Inputs, Liabilities, Quantitative Information [Table Text Block]

The following table presents the quantitative information which was used to estimate the fair values of the Level 3 assets and liabilities above as of March 31, 2016 (dollars in thousands):

	Fair Value (Net) at
	March 31, 2016			Valuation Technique	Unobservable Input	Range
Power exchange agreement	$	(20,193	)	Surrogate facility pricing	O&M charges	$33.52-$43.65/MWh (1)
					Escalation factor	3% - 2016 to 2019
					Transaction volumes	396,984 - 397,030 MWhs
Power option agreement	$	(97	)	Black-Scholes- Merton	Strike price	$33.93/MWh - 2016
						$48.25/MWh - 2019
					Delivery volumes	128,403 - 285,979 MWhs
					Volatility rates	0.20 (2)
Natural gas exchange agreement	$	(6,006	)	Internally derived weighted average cost of gas	Forward purchase prices	$1.26 - $2.81/mmBTU
					Forward sales prices	$1.43 - $3.74/mmBTU
					Purchase volumes	115,000 - 310,000 mmBTUs
					Sales volumes	60,000 - 310,000 mmBTUs

Carrying Value and Estimated Fair Value of Financial Instruments

The following table sets forth the carrying value and estimated fair value of the Company’s financial instruments not reported at estimated fair value on the Condensed Consolidated Balance Sheets as of March 31, 2016 and December 31, 2015 (dollars in thousands):

	March 31, 2016				December 31, 2015
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
Long-term debt (Level 2)	$	951,000	$	1,079,527	$	951,000	$	1,055,797
Long-term debt (Level 3)	592,000		634,929		592,000		595,018
Snettisham capital lease obligation (Level 3)	63,881		64,372		64,455		63,150
Long-term debt to affiliated trusts (Level 3)	51,547		37,114		51,547		36,083

Fair Value of Assets And Liabilities Measured on Recurring Basis

	Level 1		Level 2		Level 3		Counterparty and Cash Collateral Netting (1)			Total
March 31, 2016
Assets:
Energy commodity derivatives	$	—	$	76,124	$	—	$	(75,912	)	$	212
Level 3 energy commodity derivatives:
Natural gas exchange agreement	—		—		259		(259		)	—
Foreign currency derivatives	—		64		—		—			64
Interest rate swaps	—		894		—		(443		)	451
Deferred compensation assets:
Fixed income securities (2)	1,759		—		—		—			1,759
Equity securities (2)	5,182		—		—		—			5,182
Total	$	6,941	$	77,082	$	259	$	(76,614	)	$	7,668
Liabilities:
Energy commodity derivatives	$	—	$	98,491	$	—	$	(95,884	)	$	2,607
Level 3 energy commodity derivatives:
Natural gas exchange agreement	—		—		6,265		(259		)	6,006
Power exchange agreement	—		—		20,193		—			20,193
Power option agreement	—		—		97		—			97
Interest rate swaps	—		145,409		—		(76,443		)	68,966
Total	$	—	$	243,900	$	26,555	$	(172,586	)	$	97,869

	Level 1		Level 2		Level 3		Counterparty and Cash Collateral Netting (1)			Total
December 31, 2015
Assets:
Energy commodity derivatives	$	—	$	74,637	$	—	$	(73,954	)	$	683
Level 3 energy commodity derivatives:
Natural gas exchange agreement	—		—		678		(678		)	—
Foreign currency derivatives	—		2		—		(2		)	—
Interest rate swaps	—		1,548		—		—			1,548
Deferred compensation assets:
Fixed income securities (2)	1,727		—		—		—			1,727
Equity securities (2)	5,761		—		—		—			5,761
Total	$	7,488	$	76,187	$	678	$	(74,634	)	$	9,719
Liabilities:
Energy commodity derivatives	$	—	$	97,193	$	—	$	(88,480	)	$	8,713
Level 3 energy commodity derivatives:
Natural gas exchange agreement	—		—		5,717		(678		)	5,039
Power exchange agreement	—		—		21,961		—			21,961
Power option agreement	—		—		124		—			124
Interest rate swaps	—		85,498		—		—			85,498
Foreign currency derivatives	—		19		—		(2		)	17
Total	$	—	$	182,710	$	27,802	$	(89,160	)	$	121,352

(1) The Company is permitted to net derivative assets and derivative liabilities with the same counterparty when a legally enforceable master netting agreement exists. In addition, the Company nets derivative assets and derivative liabilities against any payables and receivables for cash collateral held or placed with these same counterparties.

(2) These assets are trading securities and are included in other property and investments-net on the Condensed Consolidated Balance Sheets.

Reconciliation for All Assets Measured At Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)

	Natural Gas Exchange Agreement			Power Exchange Agreement			Power Option Agreement			Total
Three months ended March 31, 2016:
Balance as of January 1, 2016	$	(5,039	)	$	(21,961	)	$	(124	)	$	(27,124	)
Total gains or losses (realized/unrealized):
Included in regulatory assets/liabilities (1)	(1,745		)	(2,432		)	27			(4,150		)
Settlements	778			4,200			—			4,978
Ending balance as of March 31, 2016 (2)	$	(6,006	)	$	(20,193	)	$	(97	)	$	(26,296	)
Three months ended March 31, 2015:
Balance as of January 1, 2015	$	(35	)	$	(23,299	)	$	(424	)	$	(23,758	)
Total gains or losses (realized/unrealized):
Included in regulatory assets/liabilities (1)	777			(6,381		)	173			(5,431		)
Settlements	75			3,777			—			3,852
Ending balance as of March 31, 2015 (2)	$	817		$	(25,903	)	$	(251	)	$	(25,337	)

(1) All gains and losses are included in other regulatory assets and liabilities. There were no gains and losses included in either net income or other comprehensive income during any of the periods presented in the table above.

(2) There were no purchases, issuances or transfers from other categories of any derivatives instruments during the periods presented in the table above.