CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Millions		Total	Common Stock		Additional Paid-in Capital	Additional paid-in capital	AOCI	Non-controlling Interests	Predecessor Member's Equity		Talen Energy Supply		Talen Energy Supply Non-controlling Interests	Talen Energy Supply Predecessor Member's Equity
Beginning balance at Dec. 31, 2012											$ 3,848		$ 18	$ 3,830
Beginning balance at Dec. 31, 2012		$ 3,848					$ 48	$ 18	$ 3,782	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(229)						1	(230)	[1]	(229)		1	(230)
Other comprehensive income (loss)		29					29		0	[1]	29			29
Distributions to predecessor member		(427)						(19)	(408)	[1]	(427)		(19)	(408)
Contributions from predecessor member		1,577							1,577	[1]	1,577			1,577
Ending balance at Dec. 31, 2013											4,798		$ 0	4,798
Ending balance at Dec. 31, 2013		4,798					77	$ 0	4,721	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		410							410	[1]	410			410
Other comprehensive income (loss)		(100)					(100)		0	[1]	(100)			(100)
Distributions to predecessor member		(1,940)							(1,940)	[1]	(1,940)			(1,940)
Contributions from predecessor member		739							739	[1]	739			739
Ending balance at Dec. 31, 2014											3,907			3,907
Ending balance at Dec. 31, 2014		3,907			$ 0	$ 0	(23)		3,930	[1]
Ending balance, shares at Dec. 31, 2014	[2]		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(341)									(341)
Other comprehensive income (loss)		(3)					(3)				(3)
Distributions to predecessor member		(410)							(410)	[1]	(412)	[3]
Contributions from predecessor member		248							248	[1]	1,152	[3]
Common stock issued for acquisition of RJS Power		902			902
Common stock issued for acquisition of RJS Power, shares	[2]		44,975
Stock issuance (shares)	[2]		10
Stock issuance expense		(2)			(2)
Stock-based compensation		2			2
Consummation of spinoff transaction	[1]	0			3,800				(3,800)
Consummation of spinoff transaction, shares	[1],[2]		83,524
Ending balance at Dec. 31, 2015											$ 4,303			$ 4,303
Ending balance at Dec. 31, 2015		$ 4,303			$ 4,702	$ (373)	$ (26)		$ 0	[1]
Ending balance, shares at Dec. 31, 2015		128,509	128,509	[2]

[1] Upon consummation of the spinoff on June 1, 2015, Talen Energy Supply's predecessor member's equity balance was transferred to Talen Energy Corporation's "Additional paid-in capital." See Note 1 for additional information on the spinoff.

[2] Shares in thousands. Each share entitles the holder to one vote on any questions presented at any stockholders' meeting.

[3] Includes the contribution of RJS Power as of the acquisition date. See Notes 1 and 6 for additional information.