DEBT AND CREDIT FACILITIES - Amounts Outstanding and Description of Terms (Details) - USD ($) $ in Millions | Jun. 26, 2019 | Jun. 30, 2019 | Jun. 30, 2019 | Dec. 31, 2018 |
Credit facilities, short-term loan facility and long-term debt | | | | |
Total credit facilities, short-term loan facility and long-term debt | | $ 2,003 | $ 2,003 | $ 2,118 |
Less: unamortized debt issuance costs and debt discount | | 10 | 10 | 10 |
Less: current portion | | 101 | 101 | 36 |
Long-term debt | | $ 1,892 | $ 1,892 | 2,072 |
2013 Term Loan Facility | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Repayments of secured debt | $ 50 | | | |
Unwind rate of interest rate swap (as a percent) | 2.81% | | | |
Senior Credit Facility due in 2021 and the Term Loan Facilities due in 2022 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Leverage ratio, actual (as a percent) | | 2.78% | 2.78% | |
Senior Credit Facility due in 2021 and the Term Loan Facilities due in 2022 | Each fiscal quarter except fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed | Maximum | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Leverage ratio, covenant (as a percent) | | | 5.00% | |
Senior Credit Facility due in 2021 and the Term Loan Facilities due in 2022 | Fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed | Maximum | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Leverage ratio, covenant (as a percent) | | | 5.50% | |
Revolving credit facility | TC PipeLines, LP Senior Credit Facility due 2021 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 0 | $ 0 | $ 40 |
Weighted average interest rate (as a percent) | | 3.61% | | 3.14% |
Maximum borrowing capacity | | $ 500 | 500 | |
Amount outstanding under credit facility | | 0 | 0 | $ 40 |
Revolving credit facility | TC PipeLines, LP Senior Credit Facility due 2021 | LIBOR | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt interest rate, at period end (as a percent) | | | | 3.77% |
Term loan | TC PipeLines, LP 2013 Term Loan Facility due 2022 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 450 | $ 450 | $ 500 |
Weighted average interest rate (as a percent) | | 3.73% | | 3.23% |
Term loan | TC PipeLines, LP 2013 Term Loan Facility due 2022 | LIBOR borrowings | LIBOR | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Stated interest rate (as a percent) | | | | 3.60% |
Debt interest rate, at period end (as a percent) | | 3.69% | 3.69% | |
Term loan | TC PipeLines, LP 2013 Term Loan Facility due 2022 | LIBOR borrowings | LIBOR | Hedges of cash flows | Interest rate swaps | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Weighted average interest rate (as a percent) | | | 3.26% | 3.26% |
Unsecured debt | TC PipeLines, LP 4.65% Senior Notes due 2021 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 350 | $ 350 | $ 350 |
Stated interest rate (as a percent) | | 4.65% | 4.65% | |
Weighted average interest rate (as a percent) | | 4.65% | | 4.65% |
Unsecured debt | TC PipeLines, LP 4.375% Senior Notes due 2025 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 350 | $ 350 | $ 350 |
Stated interest rate (as a percent) | | 4.375% | 4.375% | |
Weighted average interest rate (as a percent) | | 4.375% | | 4.375% |
Unsecured debt | TC PipeLines, LP 3.90% Senior Notes due 2027 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 500 | $ 500 | $ 500 |
Stated interest rate (as a percent) | | 3.90% | 3.90% | |
Weighted average interest rate (as a percent) | | 3.90% | | 3.90% |
Unsecured debt | GTN 5.29% Senior Notes due 2020 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Stated interest rate (as a percent) | | 5.29% | 5.29% | |
Unsecured debt | GTN 5.69% Senior Notes due 2035 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Stated interest rate (as a percent) | | 5.69% | 5.69% | |
Unsecured debt | Tuscarora Term Loan due 2020 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 24 | $ 24 | $ 24 |
Weighted average interest rate (as a percent) | | 3.62% | | 3.10% |
Unsecured debt | North Baja Term Loan Due 2021 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 50 | $ 50 | $ 50 |
Weighted average interest rate (as a percent) | | 3.56% | | 3.54% |
Unsecured debt | North Baja Term Loan Due 2021 | LIBOR | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt interest rate, at period end (as a percent) | | 3.52% | 3.52% | 3.54% |
GTN | Unsecured debt | GTN 5.29% Senior Notes due 2020 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 100 | $ 100 | $ 100 |
Weighted average interest rate (as a percent) | | 5.29% | | 5.29% |
GTN | Unsecured debt | GTN 5.69% Senior Notes due 2035 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 150 | 150 | $ 150 |
Weighted average interest rate (as a percent) | | 5.69% | | 5.69% |
GTN | Unsecured debt | Term Loan Facility due 2019 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 0 | $ 0 | $ 35 |
Weighted average interest rate (as a percent) | | | | 2.93% |
Percentage of debt to total capitalization, covenant | | | 39.90% | |
GTN | Unsecured debt | Term Loan Facility due 2019 | Maximum | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Percentage of debt to total capitalization, covenant | | | 70.00% | |
GTN | Unsecured debt | Term Loan Facility due 2019 | LIBOR | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt interest rate, at period end (as a percent) | | | | 3.30% |
PNGTS | Secured debt | PNGTS Revolving Credit Facility due 2023 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt and credit facilities | | $ 29 | $ 29 | $ 19 |
Weighted average interest rate (as a percent) | | 3.74% | | 3.55% |
Leverage ratio, covenant (as a percent) | | | 0.50% | |
PNGTS | Secured debt | PNGTS Revolving Credit Facility due 2023 | Maximum | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Leverage ratio, covenant (as a percent) | | | 5.00% | |
PNGTS | Secured debt | PNGTS Revolving Credit Facility due 2023 | LIBOR | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt interest rate, at period end (as a percent) | | 3.69% | 3.69% | 3.60% |
Tuscarora | Unsecured debt | Tuscarora Term Loan due 2020 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt service coverage, covenant (as a percent) | | | 9.44% | |
Tuscarora | Unsecured debt | Tuscarora Term Loan due 2020 | Minimum | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt service coverage, covenant (as a percent) | | | 3.00% | |
Tuscarora | Unsecured debt | Tuscarora Term Loan due 2020 | LIBOR | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Debt interest rate, at period end (as a percent) | | 3.57% | 3.57% | 3.47% |
North Baja | Unsecured debt | North Baja Term Loan Due 2021 | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Percentage of debt to total capitalization, actual | | 39.06% | 39.06% | |
North Baja | Unsecured debt | North Baja Term Loan Due 2021 | Maximum | | | | |
Credit facilities, short-term loan facility and long-term debt | | | | |
Percentage of debt to total capitalization, covenant | | | 70.00% | |