XML 51 R28.htm IDEA: XBRL DOCUMENT v3.21.2
Accounting for Derivative Instruments and Hedging Activities Derivative Assets and Liabilities (Details)
$ in Thousands, MMBTU in Millions
Jun. 30, 2021
USD ($)
MMBTU
Dec. 31, 2020
USD ($)
MMBTU
Derivative [Line Items]    
Current, Assets $ 150,371 $ 33,015
Long-term, Assets 17,848 8,805
Current, Liabilities 37,491 31,441
Long-term, Liabilities 18,566 29,833
Not Designated as Hedging Instrument [Member]    
Derivative [Line Items]    
Current, Assets 150,371 33,015
Long-term, Assets 17,848 8,805
Assets [1] 168,219 41,820
Current, Liabilities 37,491 31,441
Long-term, Liabilities 18,566 29,833
Derivative Liability [2] $ 56,057 $ 61,274
Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member]    
Derivative [Line Items]    
Derivative, Nonmonetary Notional Amount | MMBTU 308.0 320.0
Not Designated as Hedging Instrument [Member] | Electric Portfolio [Member]    
Derivative [Line Items]    
Assets $ 104,938 $ 22,544
Derivative Liability 45,039 46,922
Not Designated as Hedging Instrument [Member] | Natural Gas Portfolio [Member]    
Derivative [Line Items]    
Assets 63,281 19,276
Derivative Liability $ 11,018 $ 14,352
Not Designated as Hedging Instrument [Member] | Electric Generation Fuel [Member]    
Derivative [Line Items]    
Derivative, Nonmonetary Notional Amount | MMBTU 247.0 212.2
Not Designated as Hedging Instrument [Member] | Purchased Electricity [Member]    
Derivative [Line Items]    
Derivative, Nonmonetary Notional Amount | MMBTU 7.5 6.6
[1]
_______________
1 Balance sheet classification: Current and Long-term Unrealized gain on derivative instruments.
[2] 2 Balance sheet classification: Current and Long-term Unrealized loss on derivative instruments.