Commitments, Guarantees and Contingencies - Hydro Operations (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Forebay Rebuild [Member]
Hydro Operations [Line Items]
Estimated Capital Expenditures	$ 25
Minimum Payment Obligation in 2014	6.7
Restoration and Upgrade Work [Member]
Hydro Operations [Line Items]
Estimated Capital Expenditures	40
Additional Hydro Work [Member]
Hydro Operations [Line Items]
Estimated Capital Expenditures	$ 15

Minimum amount of other commitment maturing in the next fiscal year following the latest fiscal year for commitments not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in this taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitmentDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant