CONSOLIDATED STATEMENTS OF OPERATIONS shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares
Transmission revenues	$ 403	$ 549	$ 422
Equity earnings (Note 5)	160	173	124
Impairment of long-lived assets (Note 7)		(537)
Impairment of goodwill (Note 4)		(59)
Operation and maintenance expenses	(71)	(67)	(67)
Property taxes	(26)	(28)	(28)
General and administrative	(8)	(6)	(8)
Depreciation	78	97	97
Financial charges and other (Note 13)	(83)	(92)	(82)
Net income (loss) before taxes	297	(164)	264
Income taxes (Note 2)	1	(1)	(1)
Net Income (loss)	298	(165)	263
Net income attributable to non-controlling interests	18	17	11
Net income (loss) attributable to controlling interests	280	(182)	252
Net income (loss) attributable to controlling interest allocation (Note 14)
General Partner	5	(4)	16
TC Energy and its subsidiaries	8	13	17
Net income (loss) attributable to controlling interests	280	(182)	252
Common Units
Net income (loss) attributable to controlling interest allocation (Note 14)
Net income (loss) attributable to common units or Class B units	$ 267	$ (191)	$ 219
Net income (loss) per common unit (Note 14) - basic and diluted (in dollars per unit) | $ / shares	$ 3.74	$ (2.68)	$ 3.16
Weighted average common units outstanding (millions) - basic and diluted | shares	71.3	71.3	69.2
Common units outstanding, end of year (millions) | shares	71.3	71.3	70.6