Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents ($109 and $285 attributable to VIEs)	$ 1,284	$ 1,252
Accounts receivable, net of allowance of $6 and $13	437	598
Margin deposits and other prepaid expense	244	193
Restricted cash, current ($53 and $57 attributable to VIEs)	193	139
Derivative assets, current	339	1,051
Inventory and other current assets	335	329
Total current assets	2,832	3,562
Property, plant and equipment, net ($4,192 and $4,313 attributable to VIEs)	13,005	13,019
Restricted cash, net of current portion ($59 and $53 attributable to VIEs)	60	55
Investments	81	80
Long-term derivative assets	98	113
Other assets	473	542
Total assets	16,549	17,371
Current liabilities:
Accounts payable	382	435
Accrued interest payable	180	200
Debt, current portion ($39 and $41 attributable to VIEs)	115	104
Derivative liabilities, current	357	1,144
Income taxes payable	11	3
Other current liabilities	273	276
Total current liabilities	1,318	2,162
Debt, net of current portion ($2,660 and $2,522 attributable to VIEs)	10,635	10,321
Long-term derivative liabilities	293	279
Other long-term liabilities	247	245
Total liabilities	12,493	13,007
Commitments and contingencies (see Note 15)
Stockholders’ equity:
Preferred stock, $0.001 par value per share; authorized 100,000,000 shares, none issued and outstanding at December 31, 2012 and 2011	0	0
Common stock, $0.001 par value per share; authorized 1,400,000,000 shares, 492,495,100 shares issued and 457,048,970 shares outstanding at December 31, 2012, and 490,468,815 shares issued and 481,743,738 shares outstanding at December 31, 2011	1	1
Treasury stock, at cost, 35,446,130 and 8,725,077 shares, respectively	(594)	(125)
Additional paid-in capital	12,335	12,305
Accumulated deficit	(7,500)	(7,699)
Accumulated other comprehensive loss	(248)	(178)
Total Calpine stockholders’ equity	3,994	4,304
Noncontrolling interest	62	60
Total stockholders’ equity	4,056	4,364
Total liabilities and stockholders’ equity	$ 16,549	$ 17,371