Gas Reserves (Tables)

12 Months Ended

Dec. 31, 2020

Gas Reserves [Abstract]

Gas Reserves Table [Text Block]

The following table outlines NW Natural's net gas reserves investment at December 31:

In thousands	2020		2019
Gas reserves, current	$	11,409	$	15,278
Gas reserves, non-current	175,898		172,029
Less: Accumulated amortization	141,414		123,635
Total gas reserves(1)	45,893		63,672
Less: Deferred taxes on gas reserves	10,572		15,515
Net investment in gas reserves	$	35,321	$	48,157

(1)     The net investment in additional wells included in total gas reserves was $3.0 million and $3.8 million at December 31, 2020 and 2019, respectively.