Risk Management and Hedging Activities - PacifiCorp - Balance Sheet Location (Details) - USD ($) $ in Millions	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	$ (178)		$ (237)
Cash collateral, net receivable, offset against derivative positions	85		103
Derivative assets (liabilities), at fair value, net	(93)		(134)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	24		28
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative assets (liabilities), at fair value, net	24		28
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	81		75
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative assets (liabilities), at fair value, net	81		75
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(85)		(145)
Cash collateral, net receivable, offset against derivative positions	20		40
Derivative assets (liabilities), at fair value, net	(65)		(105)
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(198)		(195)
Cash collateral, net receivable, offset against derivative positions	65		63
Derivative assets (liabilities), at fair value, net	(133)		(132)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(132)		(188)
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	24		28
Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	81		72
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(61)		(109)
Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(176)		(179)
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	109		106
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(233)		(292)
Derivative, fair value, net	(124)		(186)
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts	195	$ 185	250	$ 253	$ 233	$ 223
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	15		25
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(3)		(4)
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	81		72
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0		0
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	11		7
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(66)		(113)
Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	2		2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(164)		(175)
PacifiCorp [Member] | Commodity derivative [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(105)		(136)
Cash collateral, net receivable, offset against derivative positions	73		75
Derivative assets (liabilities), at fair value, net	(32)		(61)
PacifiCorp [Member] | Commodity derivative [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	3		9
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative assets (liabilities), at fair value, net	3		9
PacifiCorp [Member] | Commodity derivative [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	2		0
Cash collateral, net receivable, offset against derivative positions	0		0
Derivative assets (liabilities), at fair value, net	2		0
PacifiCorp [Member] | Commodity derivative [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(23)		(56)
Cash collateral, net receivable, offset against derivative positions	14		18
Derivative assets (liabilities), at fair value, net	(9)		(38)
PacifiCorp [Member] | Commodity derivative [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, fair value, net	(87)		(89)
Cash collateral, net receivable, offset against derivative positions	59		57
Derivative assets (liabilities), at fair value, net	(28)		(32)
PacifiCorp [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	11		12
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(116)		(148)
Derivative, fair value, net	(105)		(136)
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts	102	$ 89	133	$ 128	$ 99	$ 85
PacifiCorp [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	5		10
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(2)		(1)
Derivative, fair value, net	3		9
PacifiCorp [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	2		0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	0		0
Derivative, fair value, net	2		0
PacifiCorp [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	4		2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(27)		(58)
Derivative, fair value, net	(23)		(56)
PacifiCorp [Member] | Commodity derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, gross asset including not subject to master netting arrangement	0		0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	(87)		(89)
Derivative, fair value, net	$ (87)		$ (89)