Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Revenue
Natural gas transportation	$ 428,136	$ 435,238	$ 428,656
Natural gas storage	12,883	12,609	13,797
Other	2,539	1,635	1,969
Total operating revenues	443,558	449,482	444,422
OPERATING EXPENSES:
General and administrative	49,204	47,695	51,665
Operation and maintenance	76,016	69,970	81,736
Depreciation and amortization	113,180	112,004	107,951
Regulatory debits	1,436	1,148	1,107
Taxes, other than income taxes	16,836	16,290	14,388
Regulatory charges resulting from tax rate changes	23,580	23,580	23,580
Other (income) expenses, net	13	(38)	47
Total operating expenses	280,265	270,649	280,474
OPERATING INCOME	163,293	178,833	163,948
OTHER (INCOME) AND OTHER EXPENSES:
Interest expense	29,986	29,712	29,232
Allowance for equity and borrowed funds used during construction	(1,606)	(669)	(3,418)
Miscellaneous other (income) expenses, net	(595)	(1,296)	(4,533)
Total other (income) and other expenses	27,785	27,747	21,281
NET INCOME	$ 135,508	$ 151,086	$ 142,667