Segment Information (Tables)

12 Months Ended

Dec. 31, 2011

Segment Reporting [Abstract]

Inter segment billing for goods and services [Table Text Block]

	2011			2010			2009
	(In millions)
Electric Utility	$	33		$	30		$	28
Gas Utility	2			—			2
Gas Storage and Pipelines	8			4			5
Power and Industrial Projects	238			161			11
Energy Trading	70			89			93
Corporate and Other	(50		)	(65		)	(74		)
	$	301		$	219		$	65

Schedule of Segment Reporting Information, by Segment [Table Text Block]

Financial data of the business segments follows:

	Operating Revenue			Depreciation, Depletion & Amortization		Interest Income			Interest Expense			Income Taxes			Net Income Attributable to DTE Energy Company			Total Assets		Goodwill		Capital Expenditures
	(In millions)
2011
Electric Utility	$	5,154		$	818	$	(1	)	$	289		$	265		$	434		$	17,370	$	1,208	$	1,203
Gas Utility	1,505			89		(7		)	64			60			110			3,933		745		179
Gas Storage and Pipelines	91			6		(5		)	7			35			57			421		22		16
Unconventional Gas Production	39			18		—			7			(3		)	(6		)	319		2		29
Power and Industrial Projects	1,129			60		(8		)	32			11			38			1,210		26		56
Energy Trading	1,276			3		—			9			34			52			552		17		1
Corporate and Other	4			1		(47		)	144			(134		)	26			2,204		—		—
Reconciliation and Eliminations	(301		)	—		58			(58		)	(1		)	—			—		—		—
Total	$	8,897		$	995	$	(10	)	$	494		$	267		$	711		$	26,009	$	2,020	$	1,484

	Operating Revenue			Depreciation, Depletion & Amortization		Interest Income			Interest Expense			Income Taxes			Net Income Attributable to DTE Energy Company			Total Assets		Goodwill		Capital Expenditures
	(In millions)
2010
Electric Utility	$	4,993		$	849	$	(1	)	$	313		$	270		$	441		$	16,375	$	1,206	$	864
Gas Utility	1,648			92		(9		)	66			67			127			3,854		759		147
Gas Storage and Pipelines	83			5		(1		)	6			32			51			391		9		5
Unconventional Gas Production	32			15		—			6			(6		)	(11		)	308		2		27
Power and Industrial Projects	1,144			60		(3		)	33			3			85			1,236		27		53
Energy Trading	875			5		—			13			5			6			483		17		1
Corporate and Other	1			1		(47		)	160			(60		)	(69		)	2,249		—		—
Reconciliation and Eliminations	(219		)	—		49			(48		)	—			—			—		—		—
Total	$	8,557		$	1,027	$	(12	)	$	549		$	311		$	630		$	24,896	$	2,020	$	1,097

	Operating Revenue			Depreciation, Depletion & Amortization		Interest Income			Interest Expense			Income Taxes			Net Income Attributable to DTE Energy Company			Total Assets		Goodwill		Capital Expenditures
	(In millions)
2009
Electric Utility	$	4,714		$	844	$	(1	)	$	324		$	228		$	376		$	15,879	$	1,206	$	794
Gas Utility	1,788			107		(8		)	68			39			80			3,832		759		166
Gas Storage and Pipelines	82			5		(1		)	10			33			49			367		9		2
Unconventional Gas Production	31			16		—			6			(4		)	(9		)	309		2		26
Power and Industrial Projects	661			40		(3		)	30			(7		)	31			1,118		31		45
Energy Trading	804			5		(1		)	10			37			75			552		17		2
Corporate & Other	—			3		(55		)	147			(79		)	(70		)	2,138		—		—
Reconciliation and Eliminations	(66		)	—		50			(50		)	—			—			—		—		—
Total	$	8,014		$	1,020	$	(19	)	$	545		$	247		$	532		$	24,195	$	2,024	$	1,035