Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

Income Tax Expense

The components of CenterPoint Houston’s income tax expense were as follows:

	Year Ended December 31,
	2010			2011		2012
	(in millions)
Current income tax expense:
Federal	$	105		$	80	$	160
State	17			19		22
Total current expense	122			99		182
Deferred income tax expense (benefit):
Federal	(5		)	146		(69		)
State	(1		)	3		—
Total deferred expense (benefit)	(6		)	149		(69		)
Total income tax expense	$	116		$	248	$	113

Reconciliation Of Expected Federal Income Tax Expense To Actual

A reconciliation of the expected federal income tax expense using the federal statutory income tax rate to the actual income tax expense and resulting effective income tax rate is as follows:

	Year Ended December 31,
	2010			2011			2012
	(in millions)
Income before income taxes and extraordinary item	$	316		$	736		$	392
Federal statutory income tax rate	35.0		%	35.0		%	35.0		%
Expected federal income tax expense	111			258			137
Increase (decrease) in tax expense resulting from:
State income tax expense, net of federal income tax	10			15			14
Amortization of investment tax credit	(7		)	(6		)	(1		)
Increase (decrease) in settled and uncertain tax positions	9			(4		)	(26		)
Other, net	(7		)	(15		)	(11		)
Total	5			(10		)	(24		)
Total income tax expense	$	116		$	248		$	113
Effective tax rate	36.7		%	33.7		%	28.8		%

Income Tax Asset Liability Disclosure

The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities were as follows:

	December 31,
	2011		2012
	(in millions)
Deferred tax assets:
Current:
Allowance for doubtful accounts	$	1	$	1
Other	2		—
Total current deferred tax assets	3		1
Non-current:
Employee benefits	94		95
Other	10		9
Total non-current deferred tax assets	104		104
Total deferred tax assets	107		105
Deferred tax liabilities:
Non-current:
Depreciation	943		1,103
Regulatory assets, net	1,274		1,098
Total deferred tax liabilities	2,217		2,201
Accumulated deferred income taxes, net	$	2,110	$	2,096

Rollforward Of Unrecognized Tax Benefits

Uncertain Income Tax Positions. The following table reconciles the beginning and ending balance of CenterPoint Houston’s unrecognized tax benefits:

	December 31,
	2010			2011			2012
	(in millions)
Balance, beginning of year	$	175		$	232		$	44
Tax Positions related to prior years:
Additions	10			—			—
Reductions	(3		)	(192		)	(46		)
Tax Positions related to current year:
Additions	50			4			—
Settlements	—			—			2
Balance, end of year	$	232		$	44		$	—