CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income (loss)	$ (341)	$ 410	$ (229)
Amounts arising during the period - gains (losses), net of tax (expense) benefit:
Available-for-sale securities, net of tax	(6)	35	67
Defined benefit plans:
Prior service costs, net of tax	(3)	8	2
Net actuarial gain, net of tax	46	(120)	71
Reclassifications from AOCI - (gains) losses, net of tax expense (benefit):
Available-for-sale securities, net of tax	(2)	(6)	(6)
Qualifying derivatives, net of tax	(19)	(25)	(123)
Defined benefit plans:
Prior service costs, net of tax	(1)	3	4
Net actuarial loss, net of tax	(18)	5	14
Total other comprehensive income (loss)	(3)	(100)	29
Comprehensive income (loss)	(344)	310	(200)
Comprehensive income attributable to noncontrolling interests	0	0	1
Comprehensive income (loss) attributable to member	(344)	310	(201)
Talen Energy Supply
Net income (loss)	(341)	410	(229)
Amounts arising during the period - gains (losses), net of tax (expense) benefit:
Available-for-sale securities, net of tax	(6)	35	67
Defined benefit plans:
Prior service costs, net of tax	(3)	8	2
Net actuarial gain, net of tax	46	(120)	71
Reclassifications from AOCI - (gains) losses, net of tax expense (benefit):
Available-for-sale securities, net of tax	(2)	(6)	(6)
Qualifying derivatives, net of tax	(19)	(25)	(123)
Defined benefit plans:
Prior service costs, net of tax	(1)	3	4
Net actuarial loss, net of tax	(18)	5	14
Total other comprehensive income (loss)	(3)	(100)	29
Comprehensive income (loss)	(344)	310	(200)
Comprehensive income attributable to noncontrolling interests	0	0	1
Comprehensive income (loss) attributable to member	$ (344)	$ 310	$ (201)