Consolidated Statement Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income from Continuing Operations	$ 585	$ 593	$ 518
Pension and other postretirement activity, net of income taxes (benefit)	6	(12)	30
Comprehensive Income (Loss) from Continuing Operations	591	581	548
Less: Comprehensive Income from Continuing Operations Attributable to Noncontrolling Interests	6	6	6
Comprehensive Income from Continuing Operations Attributable to Ameren Corporation	585	575	542
Income (Loss) from Discontinued Operations, Net of Tax (Note 16)	51	(1)	(223)
Comprehensive Income from Continuing Operations Attributable to Ameren Corporation		0	(18)
Comprehensive Income (Loss) from Discontinued Operations	51	(1)	(241)
Less: Comprehensive Income from Discontinuing Operations Attributable to Noncontrolling Interest		0	1
Comprehensive Income (Loss) from Discontinued Operations Attributable to Ameren Corporation	51	(1)	(242)
Comprehensive Income (Loss)	636	574	300
Ameren Illinois Company
Pension and other postretirement activity, net of income taxes (benefit)	(3)	(3)	(3)
Comprehensive Income (Loss)	$ 214	$ 201	$ 160