Fair Value (Nonrecurring Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
Discounted Cash Flow [Member] | Long Lived Assets Held And Used [Member] | Kelanitissa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Weighted Average Cost Of Capital Input	11.90%
Discounted Cash Flow [Member] | Minimum | Long Lived Assets Held And Used [Member] | Kelanitissa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Annual Revenue Growth Input	(9.00%)
Pretax Operating Margin Input	(4.00%)
Discounted Cash Flow [Member] | Maximum | Long Lived Assets Held And Used [Member] | Kelanitissa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Annual Revenue Growth Input	4.00%
Pretax Operating Margin Input	16.00%
Discounted Cash Flow [Member] | Weighted Average | Long Lived Assets Held And Used [Member] | Kelanitissa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Annual Revenue Growth Input	(1.00%)
Pretax Operating Margin Input	(1.00%)
Market Approach [Member] | Minimum | Long Lived Assets Held For Sale [Member] | Wind Turbines [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Indicative offer prices	12
Market Approach [Member] | Maximum | Long Lived Assets Held For Sale [Member] | Wind Turbines [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Indicative offer prices	38
Market Approach [Member] | Weighted Average | Long Lived Assets Held For Sale [Member] | Wind Turbines [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Indicative offer prices	25