Commitments and Contingencies (Schedule of Guarantor Obligations) (Details) $ in Millions	Dec. 31, 2015 USD ($)
Loans Payable [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations Balance On First Anniversary	$ 36	[1]
Guarantee Obligations Balance On Second Anniversary	26	[1]
Guarantee Obligations Balance On Third Anniversary	31	[1]
Guarantee Obligations Balance On Fourth Anniversary	30	[1]
Guarantee Obligations Balance On Fifth Anniversary	30	[1]
Guarantee Obligations Due After Five Years	118	[1]
Guarantor Obligations, Maximum Exposure, Undiscounted	271	[1]
Financial Standby Letter of Credit [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations Balance On First Anniversary	656	[2],[3],[4]
Guarantee Obligations Balance On Second Anniversary	40	[2],[3],[4]
Guarantee Obligations Balance On Third Anniversary	0	[2],[3],[4]
Guarantee Obligations Balance On Fourth Anniversary	21	[2],[3],[4]
Guarantee Obligations Balance On Fifth Anniversary	0	[2],[3],[4]
Guarantee Obligations Due After Five Years	38	[2],[3],[4]
Guarantor Obligations, Maximum Exposure, Undiscounted	755	[2],[3],[4]
Surety Bonds [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations Balance On First Anniversary	0	[4],[5],[6]
Guarantee Obligations Balance On Second Anniversary	0	[4],[5],[6]
Guarantee Obligations Balance On Third Anniversary	0	[4],[5],[6]
Guarantee Obligations Balance On Fourth Anniversary	0	[4],[5],[6]
Guarantee Obligations Balance On Fifth Anniversary	0	[4],[5],[6]
Guarantee Obligations Due After Five Years	5	[4],[5],[6]
Guarantor Obligations, Maximum Exposure, Undiscounted	5	[4],[5],[6]
Gurantee Obligations Total [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations Balance On First Anniversary	692
Guarantee Obligations Balance On Second Anniversary	66
Guarantee Obligations Balance On Third Anniversary	31
Guarantee Obligations Balance On Fourth Anniversary	51
Guarantee Obligations Balance On Fifth Anniversary	30
Guarantee Obligations Due After Five Years	161
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] Letters of credit are renewed annually and as such all amounts are reflected in the year of letter of credit expiration. The related commercial obligations extend for multiple years, therefore, renewal of the letter of credit will likely follow the term of the associated commercial obligation.

[3] The standby letters of credit disclosed above represent those disclosed in Note 6.

[4] These are contingent off balance sheet obligations.

[5] As of December 31, 2015, no cash collateral is outstanding related to these bonds.

[6] The majority of surety bonds do not have expiration or cancellation dates.