Fair Value Measurements Carrying Value (Details) (Carrying Value [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
PUGET ENERGY [Member]
Assets:
Cash and Cash Equivalents	$ 27,604	$ 135,542
Restricted Cash	4,723	3,700
Notes Receivable and Other	55,985	63,802
Total assets	88,312	203,044
Liabilities:
Short-term Debt	0	181,000
Total liabilities	0	181,000
PUGET ENERGY [Member] | Level 1 [Member]
Assets:
Cash and Cash Equivalents	12,000	105,000
Restricted Cash	2,405	914
Notes Receivable and Other	0	0
Total assets	14,405	105,914
Liabilities:
Short-term Debt	0	181,000
Total liabilities	0	181,000
PUGET ENERGY [Member] | Level 2 [Member]
Assets:
Cash and Cash Equivalents	15,604	30,542
Restricted Cash	2,318	2,786
Notes Receivable and Other	55,985	63,802
Total assets	73,907	97,130
Liabilities:
Short-term Debt	0	0
Total liabilities	0	0
Subsidiaries [Member]
Assets:
Cash and Cash Equivalents	27,463	135,530
Restricted Cash	4,723	3,700
Notes Receivable and Other	55,985	63,802
Total assets	88,171	203,032
Liabilities:
Short-term Debt	0	181,000
Short-term Debt owed by PSE to PE	29,598	29,598
Total liabilities	29,598	210,598
Subsidiaries [Member] | Level 1 [Member]
Assets:
Cash and Cash Equivalents	12,000	105,000
Restricted Cash	2,405	914
Notes Receivable and Other	0	0
Total assets	14,405	105,914
Liabilities:
Short-term Debt	0	181,000
Short-term Debt owed by PSE to PE	0	0
Total liabilities	0	181,000
Subsidiaries [Member] | Level 2 [Member]
Assets:
Cash and Cash Equivalents	15,463	30,530
Restricted Cash	2,318	2,786
Notes Receivable and Other	55,985	63,802
Total assets	73,766	97,118
Liabilities:
Short-term Debt	0	0
Short-term Debt owed by PSE to PE	29,598	29,598
Total liabilities	$ 29,598	$ 29,598