Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Revenues:
Natural gas sales	$ 88,328	$ 80,351	$ 105,884
Natural gas transportation	2,378,940	2,241,760	2,188,058
Natural gas storage	167,800	161,956	147,687
Other	19,732	20,246	11,113
Total operating revenues	2,654,800	2,504,313	2,452,742
Operating Costs and Expenses:
Cost of natural gas sales	88,328	80,351	105,884
Operation and maintenance	413,882	376,747	432,786
Administrative and general	220,378	184,768	217,000
Depreciation and amortization	489,524	463,757	433,480
Taxes — other than income taxes	92,661	83,687	76,632
Impairment of assets	2,336	170,128	0
Regulatory credit resulting from tax rate changes	(30,752)	(30,752)	(24,202)
Other expense, net	11,105	5,461	6,195
Total operating costs and expenses	1,287,462	1,334,147	1,247,775
Operating Income	1,367,338	1,170,166	1,204,967
Other (Income) and Other Expenses:
Interest expense - affiliate	53	892	2,319
Interest expense - other	322,645	311,451	283,990
Interest income - affiliate	(123)	(132)	(89)
Interest income - other	(4,591)	(4,265)	(4,349)
Allowance for equity and borrowed funds used during construction (AFUDC)	(22,125)	(22,648)	(39,289)
Equity in earnings of unconsolidated affiliates	0	0	(3,216)
Miscellaneous other (income) expenses, net	5,311	4,832	2,305
Total other (income) and other expenses	301,170	290,130	241,671
Net Income	1,066,168	880,036	963,296
Other comprehensive income:
Equity interest in unrealized gain on interest rate hedges (includes $(162) for the year ended December 31, 2019 of accumulated other comprehensive income reclassification for equity interest in realized losses (gains) on interest rate hedges)	0	0	(641)
Comprehensive Income	$ 1,066,168	$ 880,036	$ 962,655