v2.4.0.6
Commitments and Contingencies (Schedule of Guarantor Obligations) (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Loans Payable [Member]
  
Guarantor Obligations [Line Items]  
Guarantee Obligations Balance On First Anniversary $ 47 [1]
Guarantee Obligations Balance On Second Anniversary 36 [1]
Guarantee Obligations Balance On Third Anniversary 37 [1]
Guarantee Obligations Balance On Fourth Anniversary 36 [1]
Guarantee Obligations Balance On Fifth Anniversary 26 [1]
Guarantee Obligations Due After Five Years 209 [1]
Guarantor Obligations, Maximum Exposure, Undiscounted 391 [1]
Financial Standby Letter of Credit [Member]
  
Guarantor Obligations [Line Items]  
Guarantee Obligations Balance On First Anniversary 536 [2],[3]
Guarantee Obligations Balance On Second Anniversary 41 [2],[3]
Guarantee Obligations Balance On Third Anniversary 0 [2],[3]
Guarantee Obligations Balance On Fourth Anniversary 0 [2],[3]
Guarantee Obligations Balance On Fifth Anniversary 19 [2],[3]
Guarantee Obligations Due After Five Years 30 [2],[3]
Guarantor Obligations, Maximum Exposure, Undiscounted 626 [2],[3]
Surety Bonds [Member]
  
Guarantor Obligations [Line Items]  
Guarantee Obligations Balance On First Anniversary 0 [2],[4],[5]
Guarantee Obligations Balance On Second Anniversary 0 [2],[4],[5]
Guarantee Obligations Balance On Third Anniversary 0 [2],[4],[5]
Guarantee Obligations Balance On Fourth Anniversary 0 [2],[4],[5]
Guarantee Obligations Balance On Fifth Anniversary 0 [2],[4],[5]
Guarantee Obligations Due After Five Years 4 [2],[4],[5]
Guarantor Obligations, Maximum Exposure, Undiscounted 4 [2],[4],[5]
Greenleaf [Member]
  
Guarantor Obligations [Line Items]  
Guarantee Obligations Balance On First Anniversary 7
Guarantee Obligations Balance On Second Anniversary 3
Guarantee Obligations Balance On Third Anniversary 0
Guarantee Obligations Balance On Fourth Anniversary 0
Guarantee Obligations Balance On Fifth Anniversary 0
Guarantee Obligations Due After Five Years 0
Guarantor Obligations, Maximum Exposure, Undiscounted 10 [2]
Gurantee Obligations Total [Member]
  
Guarantor Obligations [Line Items]  
Guarantee Obligations Balance On First Anniversary 590
Guarantee Obligations Balance On Second Anniversary 80
Guarantee Obligations Balance On Third Anniversary 37
Guarantee Obligations Balance On Fourth Anniversary 36
Guarantee Obligations Balance On Fifth Anniversary 45
Guarantee Obligations Due After Five Years 243
Guarantor Obligations, Maximum Exposure, Undiscounted $ 1,031
[1] Represents Calpine Corporation guarantees of certain power plant capital leases and related interest. All guaranteed capital leases are recorded on our Consolidated Balance Sheets.
[2] These are contingent off balance sheet obligations.
[3] The standby letters of credit disclosed above represent those disclosed in Note 6.
[4] The majority of surety bonds do not have expiration or cancellation dates.
[5] As of December 31, 2012, $3 million of cash collateral is outstanding related to these bonds.