Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Notional Amounts of Outstanding Derivative Positions

The following table presents the absolute notional amounts related to open positions on our derivative instruments:

	September 30,				December 31,
In thousands	2017		2016		2016
Natural gas (in therms):
Financial	521,080		537,100		477,430
Physical	750,650		621,230		535,450
Foreign exchange	$	6,933	$	8,404	$	7,497

Income Statement Presentation of Derivative Instruments

The following table reflects the income statement presentation for the unrealized gains and losses from our derivative instruments:

	Three Months Ended September 30,
	2017						2016
In thousands	Natural gas commodity			Foreign exchange			Natural gas commodity			Foreign exchange
Benefit (expense) to cost of gas	$	(2,566	)	$	51		$	(8,045	)	$	(52	)
Operating gain (loss)	28			—			(110		)	—
Amounts deferred to regulatory accounts on balance sheet	2,548			(51		)	8,118			52
Total gain (loss) in pre-tax earnings	$	10		$	—		$	(37	)	$	—

	Nine Months Ended September 30,
	2017						2016
In thousands	Natural gas commodity			Foreign exchange			Natural gas commodity			Foreign exchange
Benefit (expense) to cost of gas	$	(19,081	)	$	275		$	5,562		$	5
Operating loss	(1,249		)	—			(266		)	—
Amounts deferred to regulatory accounts on balance sheet	19,895			(275		)	(5,385		)	(5		)
Total loss in pre-tax earnings	$	(435	)	$	—		$	(89	)	$	—

Table of Estimated Collateral Calls Table

Based upon current commodity financial swap and option contracts outstanding, which reflect unrealized losses of $12.0 million at September 30, 2017, we have estimated the level of collateral demands, with and without potential adequate assurance calls, using current gas prices and various credit downgrade rating scenarios for NW Natural as follows:

			Credit Rating Downgrade Scenarios
In thousands	(Current Ratings) A+/A3		BBB+/Baa1		BBB/Baa2		BBB-/Baa3			Speculative
With Adequate Assurance Calls	$	—	$	—	$	—	$	(3,138	)	$	(9,146	)
Without Adequate Assurance Calls	—		—		—		(3,138		)	(7,113		)