Fair Value (Tables)

9 Months Ended

Sep. 30, 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 September 30, 2016 (dollars in thousands):

	Fair Value (Net) at
	September 30, 2016			Valuation Technique	Unobservable Input	Range
Power exchange agreement	$	(16,310	)	Surrogate facility pricing	O&M charges	$33.59-$49.15/MWh (1)
					Escalation factor	3% - 2017 to 2019
					Transaction volumes	396,984 - 406,909 MWhs
Power option agreement	$	(797	)	Black-Scholes- Merton	Strike price	$37.46/MWh - 2019
						$49.71/MWh - 2017
					Delivery volumes	157,517 - 285,979 MWhs
					Volatility rates	0.21 (2)
Natural gas exchange agreement	$	(6,521	)	Internally derived weighted average cost of gas	Forward purchase prices	$1.95 - $2.55/mmBTU
					Forward sales prices	$2.03 - $3.37/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 September 30, 2016 and December 31, 2015 (dollars in thousands):

	September 30, 2016				December 31, 2015
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
Long-term debt (Level 2)	$	951,000	$	1,100,059	$	951,000	$	1,055,797
Long-term debt (Level 3)	502,000		572,112		592,000		595,018
Snettisham capital lease obligation (Level 3)	62,734		64,800		64,455		63,150
Long-term debt to affiliated trusts (Level 3)	51,547		38,145		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
September 30, 2016
Assets:
Energy commodity derivatives	$	—	$	33,589	$	—	$	(32,869	)	$	720
Level 3 energy commodity derivatives:
Natural gas exchange agreement	—		—		25		(25		)	—
Foreign currency derivatives	—		27		—		(25		)	2
Interest rate swaps	—		386		—		(386		)	—
Deferred compensation assets:
Fixed income securities (2)	1,895		—		—		—			1,895
Equity securities (2)	5,627		—		—		—			5,627
Total	$	7,522	$	34,002	$	25	$	(33,305	)	$	8,244
Liabilities:
Energy commodity derivatives	$	—	$	55,233	$	—	$	(50,831	)	$	4,402
Level 3 energy commodity derivatives:
Natural gas exchange agreement	—		—		6,546		(25		)	6,521
Power exchange agreement	—		—		16,310		—			16,310
Power option agreement	—		—		797		—			797
Foreign currency derivatives	—		25		—		(25		)	—
Interest rate swaps	—		154,770		—		(64,746		)	90,024
Total	$	—	$	210,028	$	23,653	$	(115,627	)	$	118,054

	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
Foreign currency derivatives	—		19		—		(2		)	17
Interest rate swaps	—		85,498		—		—			85,498
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 and other non-current assets 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 September 30, 2016:
Balance as of July 1, 2016	$	(6,857	)	$	(14,614	)	$	(105	)	$	(21,576	)
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities (1)	336			(1,696		)	(692		)	(2,052		)
Settlements	—			—			—			—
Ending balance as of September 30, 2016 (2)	$	(6,521	)	$	(16,310	)	$	(797	)	$	(23,628	)
Three months ended September 30, 2015:
Balance as of July 1, 2015	$	(6,825	)	$	(18,616	)	$	(145	)	$	(25,586	)
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities (1)	1,800			(4,563		)	28			(2,735		)
Settlements	282			—			—			282
Ending balance as of September 30, 2015 (2)	$	(4,743	)	$	(23,179	)	$	(117	)	$	(28,039	)
Nine months ended September 30, 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)	(2,960		)	272			(673		)	(3,361		)
Settlements	1,478			5,379			—			6,857
Ending balance as of September 30, 2016 (2)	$	(6,521	)	$	(16,310	)	$	(797	)	$	(23,628	)
Nine months ended September 30, 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)	(5,586		)	(4,393		)	307			(9,672		)
Settlements	878			4,513			—			5,391
Ending balance as of September 30, 2015 (2)	$	(4,743	)	$	(23,179	)	$	(117	)	$	(28,039	)

(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.