Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2019

Derivative Instruments

Schedule of notional volume of natural gas derivatives that is expected to settle or mature each year

The following table reflects the notional volume of our natural gas derivatives as of September 30, 2019 that is expected to settle or mature each year:

	Natural GasSwaps
	(MMBTUs)
Year	(in millions)
2019	3.5
2020	24.9
2021	22.0
2022	15.3
2023	10.2
2024	7.2
Total	83.1

Schedule of fair value of derivative instruments and effect on consolidated balance sheets

	Balance Sheet
	Location	Fair Value
		2019		2018
		(dollars in thousands)
Assets:
Natural gas swaps	Other current assets	$	—	$	226
Liabilities:
Natural gas swaps	Other current liabilities	$	10,435	$	2,066
Natural gas swaps	Other deferred credits	$	15,944	$	11,314

Schedule of the realized gains and (losses) on derivative instruments recognized in margin

	Statement of	Three months				Nine months
	Revenues and	ended				ended
	Expenses	September 30,				September 30,
	Location	2019		2018		2019		2018
		(dollars in thousands)
Natural Gas Swaps gains	Fuel	$	—	$	863	$	224	$	2,614
Natural Gas Swaps losses	Fuel		(6,294)		(97)		(8,093)		(956)
Total		$	(6,294)	$	766	$	(7,869)	$	1,658

Schedule of unrealized losses on derivative instruments deferred on the balance sheet

	Balance Sheet
	Location	2019		2018
		(dollars in thousands)
Natural gas swaps	Regulatory asset	$	26,379	$	13,154
Total		$	26,379	$	13,154