Accounting for Derivative Instruments and Hedging Activities Net Amount of Derivatives Reported in the Statement of Financial Position (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Commodity Contract [Member]		Dec. 31, 2013 Commodity Contract [Member]		Jun. 30, 2014 Interest Rate Contract [Member]		Dec. 31, 2013 Interest Rate Contract [Member]
Derivative [Line Items]
Derivative contracts classified as financing activities due to merger	$ (8,026)	$ (26,013)
Assets
Gross Amount Recognized in the Statement of Financial Position			52,083	[1]	26,600	[1]
Gross Amounts Offset in the Statement of Financial Position			0		0
Net of Amounts Presented in the Statement of Financial Position			52,083		26,600
Commodity Contracts			(22,446)		(19,491)
Cash Collateral Received			0		0
Net Amount			29,637		7,109
Liabilities
Gross Amount Recognized in the Statement of Financial Position			33,102	[1]	72,988	[1]	12,349	[1],[2]	13,223	[1],[2]
Gross Amounts Offset in the Statement of Financial Position			0		0		0	[2]	0	[2]
Net of Amounts Presented in the Statement of Financial Position			33,102		72,988		12,349	[2]	13,223	[2]
Commodity Contracts			(22,446)		(19,491)		0	[2]	0	[2]
Cash Collateral Posted			43		0		0	[2]	0	[2]
Net Amount			$ 10,699		$ 53,497		$ 12,349	[2]	$ 13,223	[2]

[1] 1 All Derivative Contract deals are executed under ISDA, NAESB and WSPP Master Netting Agreements with Right of Offset.

[2] 2 Interest Rate Swap Contracts are only held at Puget Energy.