Other Income and Expenses (Tables)

3 Months Ended

Mar. 31, 2013

Other Nonoperating Income (Expense) [Abstract]

Other Income And Expenses

	Three Months
	2013		2012
Ameren:(a)
Miscellaneous income:
Allowance for equity funds used during construction	$	8	$	9
Interest income on industrial development revenue bonds	7		7
Other	—		1
Total miscellaneous income	$	15	$	17
Miscellaneous expense:
Donations	$	4	$	12	(b)
Other	4		3
Total miscellaneous expense	$	8	$	15
Ameren Missouri:
Miscellaneous income:
Allowance for equity funds used during construction	$	7	$	8
Interest income on industrial development revenue bonds	7		7
Total miscellaneous income	$	14	$	15
Miscellaneous expense:
Donations	$	2	$	2
Other	3		1
Total miscellaneous expense	$	5	$	3
Ameren Illinois:
Miscellaneous income:
Allowance for equity funds used during construction	$	1	$	1
Total miscellaneous income	$	1	$	1
Miscellaneous expense:
Donations	$	3	$	10	(b)
Other	—		1
Total miscellaneous expense	$	3	$	11

(a) Includes amounts for Ameren registrant and nonregistrant subsidiaries and intercompany eliminations.

(b) Includes Ameren Illinois’ one-time $7.5 million donation to the Illinois Science and Energy Innovation Trust pursuant to the IEIMA as a result of Ameren Illinois’ 2012 participation in the formula ratemaking process.