Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Revenues:
Natural gas sales	$ 105,884	$ 127,821	$ 99,100
Natural gas transportation	2,188,058	1,784,794	1,531,778
Natural gas storage	147,687	136,666	137,348
Other	11,113	10,600	6,779
Total operating revenues	2,452,742	2,059,881	1,775,005
Operating Costs and Expenses:
Cost of natural gas sales	105,884	127,821	99,100
Cost of natural gas transportation	50,273	38,749	19,589
Operation and maintenance	382,513	399,293	401,871
Administrative and general	217,000	189,588	182,121
Depreciation and amortization	433,480	366,566	318,058
Taxes — other than income taxes	76,632	67,537	65,612
Regulatory charge (credit) resulting from Tax Reform	(24,202)	(20,867)	471,096
Other expense, net	6,195	64,918	63,644
Total operating costs and expenses	1,247,775	1,233,605	1,621,091
Operating Income	1,204,967	826,276	153,914
Other (Income) and Other Expenses:
Interest expense - affiliate	2,319	60	60
- other	283,990	218,126	158,814
Interest income - affiliate	(89)	(7,606)	(3,507)
- other	(4,349)	(3,448)	(2,782)
Allowance for equity and borrowed funds used during construction (AFUDC)	(39,289)	(116,347)	(92,013)
Equity in (earnings) loss of unconsolidated affiliates	(3,216)	(1,068)	6,188
Miscellaneous other (income) expenses, net	2,305	(4,520)	31,426
Total other (income) and other expenses	241,671	85,197	98,186
Net Income	963,296	741,079	55,728
Other comprehensive income:
Equity interest in unrealized gain on interest rate hedges (includes $(162), $(143), and $103 for the years ended December 31, 2019, 2018, and 2017, respectively, of accumulated other comprehensive income reclassification for equity interest in realized losses (gains) on interest rate hedges)	(641)	197	327
Comprehensive Income	$ 962,655	$ 741,276	$ 56,055