Debt (Tables)

3 Months Ended

Mar. 31, 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.

	March 31, 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		$	125,975	$	125,000		$	126,673
Notes, 6.1%, due 2041	125,000			178,950		125,000			162,666
Notes, 3.875%, due 2022	250,000			252,688		250,000			258,550
Notes, 4.875%, due 2043	250,000			290,645		250,000			291,928
Notes, 3.8%, due 2046	300,000			278,106		300,000			308,307
Notes, 3.7%, due 2028	300,000			311,565		300,000			320,685
Notes, 4.15%, due 2049	300,000			297,987		300,000			330,138
8% Series, due 2026	75,000			96,435		75,000			96,905
Medium-term notes, 7.78% series, due 2022	25,000			27,293		25,000			27,500
Medium-term notes, 7.92% series, due 2027	25,000			32,621		25,000			32,543
Medium-term notes, 6.76% series, due 2027	7,500			9,185		7,500			9,156
Unamortized discount and debt issuance costs	(14,220		)			(14,450		)
	1,768,280					1,768,050
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	(1,656		)			(1,717		)
	198,344					198,283
Less: current maturities	(125,000		)			(125,000		)
Long-term debt, less current maturities - Southwest Gas Corporation	$	1,991,624				$	1,991,333
Centuri:
Centuri term loan facility	$	232,642		$	228,304	$	244,812		$	252,182
Unamortized debt issuance costs	(1,031		)			(1,101		)
	231,611					243,711
Centuri secured revolving credit facility	42,666			42,658		60,021			60,057
Centuri other debt obligations	88,757			87,758		43,929			44,787
Less: current maturities	(44,574		)			(38,512		)
Long-term debt, less current maturities - Centuri	$	318,460				$	309,149
Consolidated Southwest Gas Holdings, Inc.:
Southwest Gas Corporation long-term debt	$	2,116,624				$	2,116,333
Centuri long-term debt	363,034					347,661
Less: current maturities	(169,574		)			(163,512		)
Long-term debt, less current maturities - Southwest Gas Holdings, Inc.	$	2,310,084				$	2,300,482