Cash and Cash Equivalents and Restricted Cash and Cash Equivalents Supplemental Cash Flow Disclosure - Pacificorp (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,644	$ 935
Restricted cash and cash equivalents	212	327
Restricted Cash and Cash Equivalents, Noncurrent	20	21
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	1,876	1,283	$ 1,232	$ 1,003
PacifiCorp [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	17	14
Restricted cash and cash equivalents	13	13
Restricted Cash and Cash Equivalents, Noncurrent	2	2
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 32	$ 29	$ 30	$ 33