Consolidated Statement of Comprehensive Income (Loss) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income from Continuing Operations	$ 151	$ 106	$ 250	$ 162
Other Comprehensive Income, Net of Taxes
Pension and other postretirement benefit plan activity, net of income taxes (benefit)	3	10	3	10
Comprehensive Income from Continuing Operations	154	116	253	172
Less: Comprehensive Income from Continuing Operations Attributable to Noncontrolling Interests	1	1	3	3
Comprehensive Income from Continuing Operations Attributable to Ameren Corporation	153	115	250	169
Loss from Discontinued Operations, Net of Taxes	(1)	(10)	(2)	(209)
Other Comprehensive Loss from Discontinued Operations, Net of Taxes		(4)		(11)
Comprehensive Loss from Discontinued Operations Attributable to Ameren Corporation	(1)	(14)	(2)	(220)
Comprehensive Income (Loss)	$ 152	$ 101	$ 248	$ (51)