DEBT

Short-Term Debt

At March 31, 2019, NW Holdings had short-term debt outstanding of $176.4 million, substantially all of which was recorded at NW Natural and was comprised primarily of NW Natural's commercial paper. The carrying cost of commercial paper approximates fair value using Level 2 inputs. See Note 2 in the 2018 Form 10-K for a description of the fair value hierarchy. At March 31, 2019, NW Natural's commercial paper had a maximum remaining maturity of 33 days and average remaining maturity of 17 days.

Long-Term Debt

At March 31, 2019, NW Holdings had long-term debt outstanding of $736.6 million, substantially all of which was recorded at NW Natural and included $5.2 million of unamortized debt issuance costs. NW Natural's long-term debt consists of first mortgage bonds (FMBs) with maturity dates ranging from 2019 through 2048, interest rates ranging from 2.822% to 9.050%, and a weighted average coupon rate of 5.009%.

Fair Value of Long-Term Debt

NW Holdings' and NW Natural's outstanding debt does not trade in active markets. The fair value of long-term debt is estimated using the value of outstanding debt at natural gas distribution companies with similar credit ratings, terms, and remaining maturities to NW Holdings' and NW Natural's debt that actively trade in public markets. Substantially all outstanding debt at NW Holdings is comprised of NW Natural debt. These valuations are based on Level 2 inputs as defined in the fair value hierarchy. See Note 2 in the 2018 Form 10-K for a description of the fair value hierarchy.

The following table provides an estimate of the fair value of NW Natural's long-term debt, including current maturities of long-term debt, using market prices in effect on the valuation date:



	March 31,						December 31,
In thousands	2019			2018			2018
Gross long-term debt	$	739,700		$	764,700		$	739,700
Unamortized debt issuance costs	(5,246		)	(6,418		)	(5,577		)
Carrying amount	$	734,454		$	758,282		$	734,123
Estimated fair value⁽¹⁾	$	775,590		$	807,288		$	760,222

⁽¹⁾Estimated fair value does not include unamortized debt issuance costs.