Selected Quarterly Information (Tables)

12 Months Ended

Dec. 31, 2013

Selected Quarterly Financial Information [Abstract]

Summary Of Selected Quarterly Information

SELECTED QUARTERLY INFORMATION (Unaudited) (In millions, except per share amounts)

Ameren	2013												2012
Quarter ended (a)	March 31			June 30			September 30			December 31			March 31			June 30		September 30		December 31
Operating revenues	$	1,475		$	1,403		$	1,638		$	1,322		$	1,412		$	1,402	$	1,709	$	1,258
Operating income	185			261			567			171			159			347		570		112
Net income (loss)(b)	(143		)	96			304			38			(403		)	210		374		(1,155		)
Net income attributable to Ameren Corporation – continuing operations	$	54		$	105		$	305		$	48		$	38		$	164	$	302	$	12
Net income (loss) attributable to Ameren Corporation – discontinued operations (b)	(199		)	(10		)	(3		)	(11		)	(441		)	47		72		(1,168		)
Net income (loss) attributable to Ameren Corporation	$	(145	)	$	95		$	302		$	37		$	(403	)	$	211	$	374	$	(1,156	)
Earnings per common share – basic – continuing operations	$	0.22		$	0.44		$	1.26		$	0.19		$	0.16		$	0.67	$	1.25	$	0.05
Earnings (loss) per common share – basic – discontinued operations	(0.82		)	(0.05		)	(0.01		)	(0.04		)	(1.82		)	0.20		0.29		(4.81		)
Earnings (loss) per common share – basic	$	(0.60	)	$	0.39		$	1.25		$	0.15		$	(1.66	)	$	0.87	$	1.54	$	(4.76	)
Earnings per common share – diluted – continuing operations	$	0.22		$	0.44		$	1.25		$	0.19		$	0.16		$	0.67	$	1.25	$	0.05
Earnings (loss) per common share – diluted – discontinued operations	(0.82		)	(0.05		)	(0.01		)	(0.04		)	(1.82		)	0.20		0.29		(4.81		)
Earnings (loss) per common share – diluted	$	(0.60	)	$	0.39		$	1.24		$	0.15		$	(1.66	)	$	0.87	$	1.54	$	(4.76	)

(a) The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and to changes in the number of weighted-average shares outstanding each period.

(b) Includes pretax asset impairment charge of $2.6 billion recorded in discontinued operations during the year ended December 31, 2012. See Note 16 – Divestiture Transactions and Discontinued Operations under Part II, Item 8, for additional information.

Ameren Missouri Quarter ended	Operating revenues		Operating income		Net income (loss)		Net income (loss) available to common stockholder
March 31, 2013	$	796	$	111	$	41	$	40
March 31, 2012	691		78		22		21
June 30, 2013	889		179		85		84
June 30, 2012	844		269		144		143
September 30, 2013	1,093		417		239		238
September 30, 2012	1,064		429		237		236
December 31, 2013	763		96		33		33
December 31, 2012	673		69		16		16

Ameren Illinois Quarter ended	Operating revenues		Operating income		Net income		Net income available to common stockholder
March 31, 2013	$	684	$	85	$	32	$	31
March 31, 2012	724		89		28		27
June 30, 2013	516		87		32		31
June 30, 2012	564		86		33		32
September 30, 2013	547		158		77		77
September 30, 2012	648		151		71		71
December 31, 2013	564		85		22		21
December 31, 2012	589		51		12		11