Property And Plant, Net (Tables)

12 Months Ended

Dec. 31, 2011

Property And Plant, Net [Abstract]

Schedule Of Property And Plant, Net

	Ameren(a)(b)		Ameren Missouri(b)		Ameren Illinois		Genco
2011:
Property and plant, at original cost:
Electric	$	24,256	$	14,986	$	4,600	$	3,370
Gas		1,746		385		1,361		-
Other		466		113		91		39
		26,468		15,484		6,052		3,409
Less: Accumulated depreciation and amortization		9,429		6,276		1,364		1,377
		17,039		9,208		4,688		2,032
Construction work in progress:
Nuclear fuel in process		255		255		-		-
Other		833		495		82		199
Property and plant, net	$	18,127	$	9,958	$	4,770	$	2,231
2010:
Property and plant, at original cost:
Electric	$	24,069	$	14,745	$	4,436	$	3,572
Gas		1,661		374		1,286		-
Other		424		91		61		48
		26,154		15,210		5,783		3,620
Less: Accumulated depreciation and amortization		9,194		6,052		1,250		1,518
		16,960		9,158		4,533		2,102
Construction work in progress:
Nuclear fuel in process		259		259		-		-
Other		634		358		43		146
Property and plant, net	$	17,853	$	9,775	$	4,576	$	2,248

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

(b) Amounts in Ameren and Ameren Missouri include two electric generation CTs under two separate capital lease agreements. The gross asset value of those agreements was $229 million and $228 million at December 31, 2011 and 2010, respectively. The total accumulated depreciation associated with the two CTs was $52 million and $46 million at December 31, 2011 and 2010, respectively.

Accrued Capital Expenditures

	Ameren(a)		Ameren Missouri		Ameren Illinois		Genco
2011	$	107	$	73	$	18	$	13
2010		79		53		15		8
2009		143		86		29		23

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