CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net income (loss)	$ 26	$ 13	$ 122	$ (53)
Amounts arising during the period - gains (losses), net of tax (expense) benefit:
Available-for-sale securities, net of tax	(4)	14	1	19
Defined benefit plans:
Prior service costs, net of tax	(3)	0	(3)	0
Net actuarial gain, net of tax	46	0	46	0
Reclassifications from AOCI - (gains) losses, net of tax expense (benefit):
Available-for-sale securities, net of tax	(1)	(1)	(2)	(2)
Qualifying derivatives, net of tax	(6)	(8)	(10)	(13)
Defined benefit plans:
Prior service costs, net of tax	(1)	0	(1)	1
Net actuarial loss, net of tax	5	2	9	3
Total other comprehensive income (loss)	36	7	40	8
Comprehensive income (loss)	62	20	162	(45)
Talen Energy Supply
Net income (loss)	26	13	122	(53)
Amounts arising during the period - gains (losses), net of tax (expense) benefit:
Available-for-sale securities, net of tax	(4)	14	1	19
Defined benefit plans:
Prior service costs, net of tax	(3)	0	(3)	0
Net actuarial gain, net of tax	46	0	46	0
Reclassifications from AOCI - (gains) losses, net of tax expense (benefit):
Available-for-sale securities, net of tax	(1)	(1)	(2)	(2)
Qualifying derivatives, net of tax	(6)	(8)	(10)	(13)
Defined benefit plans:
Prior service costs, net of tax	(1)	0	(1)	1
Net actuarial loss, net of tax	5	2	9	3
Total other comprehensive income (loss)	36	7	40	8
Comprehensive income (loss)	$ 62	$ 20	$ 162	$ (45)