Compensation and Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2013

Pension Plans

Defined Benefit Plan Disclosure [Line Items]

Expense Components for Plans

The following were components of pension expense:

	Three Months Ended June 30,
	2013									2012
(in millions)	Midwest Generation			Other EME Sub- sidiaries1			EME			Midwest Generation			Other EME Sub- sidiaries1		EME
Service cost	$	2		$	—		$	2		$	3		$	1	$	4
Interest cost	2			1			3			2			1		3
Expected return on plan assets	(2		)	(1		)	(3		)	(3		)	—		(3		)
Net amortization	—			2			2			1			1		2
Total expense	$	2		$	2		$	4		$	3		$	3	$	6

¹  Excludes Homer City.

	Six Months Ended June 30,
	2013									2012
(in millions)	Midwest Generation			Other EME Sub- sidiaries1			EME			Midwest Generation			Other EME Sub- sidiaries1			EME
Service cost	$	6		$	1		$	7		$	7		$	1		$	8
Interest cost	4			2			6			4			2			6
Expected return on plan assets	(5		)	(1		)	(6		)	(5		)	(1		)	(6		)
Net amortization	1			2			3			1			2			3
Total expense	$	6		$	4		$	10		$	7		$	4		$	11

¹  Excludes Homer City.

Postretirement Benefits Other Than Pensions

Defined Benefit Plan Disclosure [Line Items]

Expense Components for Plans

The following were components of postretirement benefits expense:

	Three Months Ended June 30,
	2013							2012
(in millions)	Midwest Generation		Other EME Sub- sidiaries1			EME		Midwest Generation		Other EME Sub- sidiaries1			EME
Service cost	$	0.3	$	0.3		$	0.6	$	0.4	$	0.2		$	0.6
Interest cost	0.6		0.4			1.0		0.7		0.4			1.1
Net amortization	0.4		(0.1		)	0.3		0.4		(0.1		)	0.3
Total expense	$	1.3	$	0.6		$	1.9	$	1.5	$	0.5		$	2.0

¹  Excludes Homer City.

	Six Months Ended June 30,
	2013							2012
(in millions)	Midwest Generation		Other EME Sub- sidiaries1			EME		Midwest Generation		Other EME Sub- sidiaries1			EME
Service cost	$	0.6	$	0.6		$	1.2	$	0.8	$	0.4		$	1.2
Interest cost	1.2		0.8			2.0		1.4		0.8			2.2
Net amortization	0.8		(0.2		)	0.6		0.8		(0.1		)	0.7
Total expense	$	2.6	$	1.2		$	3.8	$	3.0	$	1.1		$	4.1

¹  Excludes Homer City.