Long term debt (Tables)

12 Months Ended

Dec. 31, 2018

Long-term Debt, Unclassified [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

Long-term debt consists of the following (in millions):

	As of December 31,
	2018			2017
First Mortgage Bonds, rates range from 2.51% to 9.31%, with a weighted average rate of 5.01% in 2018 and 5.03% in 2017, due at various dates through 2048	$	2,390		$	2,315
Pollution Control Revenue Bonds, 5% rate, due 2033	119			142
Pollution Control Revenue Bonds owned by PGE	(21		)	(21		)
Total long-term debt	2,488			2,436
Less: Unamortized debt expense	(10		)	(10		)
Less: Current portion of long-term debt	(300		)	—
Long-term debt, net of current portion	$	2,178		$	2,426

Schedule of Maturities of Long-term Debt [Table Text Block]

As of December 31, 2018, the future minimum principal payments on long-term debt are as follows (in millions):

Years ending December 31:
2019	$	300
2020	—
2021	160
2022	—
2023	—
Thereafter	2,028
	$	2,488