Debt (Tables)

6 Months Ended

Jun. 30, 2020

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’s other debt obligations (not actively traded) are categorized as Level 3. Because Centuri’s debt is not publicly traded, fair values for its secured revolving credit and term loan facility and other debt obligations were based on a conventional discounted cash flow methodology utilizing 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.

	June 30, 2020				December 31, 2019
	Carrying Amount		Market Value		Carrying Amount		Market Value
(Thousands of dollars)
Southwest Gas Corporation:
Debentures:
Notes, 4.45%, due 2020	$	125,000	$	125,591	$	125,000	$	126,673
Notes, 6.1%, due 2041	125,000		170,349		125,000		162,666
Notes, 3.875%, due 2022	250,000		261,013		250,000		258,550
Notes, 4.875%, due 2043	250,000		311,565		250,000		291,928
Notes, 3.8%, due 2046	300,000		328,707		300,000		308,307
Notes, 3.7%, due 2028	300,000		336,504		300,000		320,685
Notes, 4.15%, due 2049	300,000		325,410		300,000		330,138
Notes, 2.2%, due 2030	450,000		462,708		—		—
8% Series, due 2026	75,000		99,588		75,000		96,905
Medium-term notes, 7.78% series, due 2022	25,000		27,224		25,000		27,500
Medium-term notes, 7.92% series, due 2027	25,000		33,720		25,000		32,543
Medium-term notes, 6.76% series, due 2027	7,500		9,549		7,500		9,156
Unamortized discount and debt issuance costs	(18,488)				(14,450)
	2,214,012				1,768,050
Revolving credit facility and commercial paper	—		—		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	(1,594)				(1,717)
	198,406				198,283
Less: current maturities	(125,000)				(125,000)
Long-term debt, less current maturities - Southwest Gas Corporation	$	2,287,418			$	1,991,333
Centuri:
Centuri term loan facility	$	230,991	$	235,906	$	244,812	$	252,182
Unamortized debt issuance costs	(960)				(1,101)
	230,031				243,711
Centuri secured revolving credit facility	66,645		66,672		60,021		60,057
Centuri other debt obligations	101,891		104,500		43,929		44,787
Less: current maturities	(46,668)				(38,512)
Long-term debt, less current maturities - Centuri	$	351,899			$	309,149
Consolidated Southwest Gas Holdings, Inc.:
Southwest Gas Corporation long-term debt	$	2,412,418			$	2,116,333
Centuri long-term debt	398,567				347,661
Less: current maturities	(171,668)				(163,512)
Long-term debt, less current maturities - Southwest Gas Holdings, Inc.	$	2,639,317			$	2,300,482