Consolidated Condensed Statements of Operations (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Operating revenues:
Commodity revenue	$ 1,766	$ 1,539	$ 3,814	$ 2,847
Mark to Market Gain (Loss)	169	31	83	(40)
Other revenue	4	2	7	6
Operating revenues	1,939	1,572	3,904	2,813
Operating expenses:
Commodity expense	1,106	998	2,476	1,833
Mark to Market (Gain) Loss	28	2	15	(12)
Fuel and purchased energy expense	1,134	1,000	2,491	1,821
Plant operating expense	274	257	539	484
Depreciation and amortization expense	147	145	300	291
Sales, general and other administrative expense	38	36	71	69
Other operating expenses	21	20	43	38
Total operating expenses	1,614	1,458	3,444	2,703
(Income) from unconsolidated investments in power plants	(4)	(8)	(13)	(16)
Income from operations	329	122	473	126
Interest expense	169	170	335	346
Interest (income)	(2)	(1)	(3)	(3)
Debt extinguishment costs	0	68	1	68
Other (income) expense, net	6	3	16	8
Income (loss) before income taxes	156	(118)	124	(293)
Income tax expense (benefit)	15	(48)	(4)	(98)
Net income (loss)	141	(70)	128	(195)
Net income attributable to the noncontrolling interest	(2)	0	(6)	0
Net income (loss) attributable to Calpine	$ 139	$ (70)	$ 122	$ (195)
Basic earnings (loss) per common share attributable to Calpine:
Weighted average shares of common stock outstanding (in thousands)	416,507	447,558	418,296	449,620
Net income (loss) per common share attributable to Calpine — basic	$ 0.33	$ (0.16)	$ 0.29	$ (0.43)
Diluted earnings (loss) per common share attributable to Calpine:
Weighted average shares of common stock outstanding (in thousands)	421,348	447,558	422,697	449,620
Net income (loss) per common share attributable to Calpine — diluted	$ 0.33	$ (0.16)	$ 0.29	$ (0.43)