Fair Value Measurements (Assets Held For Sale) (Details) - Fair Value, Nonrecurring $ in Thousands	Dec. 31, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
BrightVolt investment	$ 341
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
BrightVolt investment	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
BrightVolt investment	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
BrightVolt investment	$ 341