Income Tax

3 Months Ended

Mar. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

The effective income tax rate varied from the federal statutory rate due to the following:

	Three Months Ended March 31,
	NW Holdings						NW Natural
In thousands	2021			2020			2021			2020
Income tax at statutory rate (federal)	$	16,808		$	13,105		$	16,939		$	13,355
State income tax	7,308			3,677			7,325			3,737
Increase (decrease):
Differences required to be flowed-through by regulatory commissions	(3,605)			(2,525)			(3,605)			(2,525)
Other, net	10			(130)			(107)			(149)
Total provision for income taxes on continuing operations	$	20,521		$	14,127		$	20,552		$	14,418
Effective income tax rate for continuing operations	25.6		%	22.8		%	25.5		%	22.8		%