Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Schedule of Carrying Amounts and Estimated Fair Values of Long-Term Debt

The Centuri secured revolving credit and term loan facility and Centuri other debt obligations (not actively traded) are categorized as Level 3, based on significant unobservable inputs to their fair values. Because Centuri’s debt is not publicly traded, fair values for the secured revolving credit and term loan facility and other debt obligations were based on a conventional discounted cash flow methodology and utilized current market pricing yield curves, across Centuri’s debt maturity spectrum, of other industrial bonds with an assumed credit rating comparable to the Company’s.

	March 31, 2019					December 31, 2018
	Carrying Amount			Market Value		Carrying Amount			Market Value
(Thousands of dollars)
Southwest Gas Corporation:
Debentures:
Notes, 4.45%, due 2020	$	125,000		$	126,990	$	125,000		$	126,213
Notes, 6.1%, due 2041	125,000			154,294		125,000			150,728
Notes, 3.875%, due 2022	250,000			255,015		250,000			254,195
Notes, 4.875%, due 2043	250,000			277,683		250,000			268,985
Notes, 3.8%, due 2046	300,000			283,635		300,000			267,030
Notes, 3.7%, due 2028	300,000			306,465		300,000			298,926
8% Series, due 2026	75,000			95,128		75,000			93,827
Medium-term notes, 7.78% series, due 2022	25,000			27,715		25,000			27,497
Medium-term notes, 7.92% series, due 2027	25,000			30,824		25,000			30,016
Medium-term notes, 6.76% series, due 2027	7,500			8,845		7,500			8,651
Unamortized discount and debt issuance costs	(11,641		)			(11,807		)
	1,470,859					1,470,693
Revolving credit facility and commercial paper	150,000			150,000		150,000			150,000
Industrial development revenue bonds:
Variable-rate bonds:
Tax-exempt Series A, due 2028	50,000			50,000		50,000			50,000
2003 Series A, due 2038	50,000			50,000		50,000			50,000
2008 Series A, due 2038	50,000			50,000		50,000			50,000
2009 Series A, due 2039	50,000			50,000		50,000			50,000
Unamortized discount and debt issuance costs	(1,900		)			(2,024		)
	198,100					197,976
Less: current maturities	—					—
Long-term debt, less current maturities - Southwest Gas Corporation	$	1,818,959				$	1,818,669
Centuri:
Centuri term loan facility	$	254,534		$	257,579	$	255,959		$	260,135
Unamortized debt issuance costs	(1,343		)			(1,414		)
	253,191					254,545
Centuri secured revolving credit facility	6,361			6,363		—			—
Centuri other debt obligations	62,678			63,365		67,104			67,053
Less: current maturities	(34,915		)			(33,060		)
Long-term debt, less current maturities - Centuri	$	287,315				$	288,589
Consolidated Southwest Gas Holdings, Inc.:
Southwest Gas Corporation long-term debt	$	1,818,959				$	1,818,669
Centuri long-term debt	322,230					321,649
Less: current maturities	(34,915		)			(33,060		)
Long-term debt, less current maturities - Southwest Gas Holdings, Inc.	$	2,106,274				$	2,107,258