Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 227	$ 183	$ 529	$ 561
Average number of common shares outstanding	172	169	171	169
Weighted average net restricted shares outstanding	1	1	1	1
Dividends declared - common shares	106	99	307	293
Dividends declared - net restricted shares	1	0	2	1
Total distributed earnings	107	99	309	294
Net income less distributed earnings	120	84	220	267
Distributed (dividends per common share)	$ 0.62	$ 0.59	$ 1.80	$ 1.74
Undistributed	$ 0.70	$ 0.49	$ 1.29	$ 1.57
Total Basic Earnings per Common Share	$ 1.32	$ 1.08	$ 3.09	$ 3.31
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	227	183	529	561
Average number of common shares outstanding	172	169	171	169
Average number of common shares Outstanding 1		169		169
Average incremental shares from assumed exercise of options	0	1	0	1
Common shares for dilutive calculation	172	170	171	170
Weighted average net restricted shares outstanding	1	1	1	1
Dividends declared - common shares	106	99	307	293
Dividends declared - net restricted shares	1	0	2	1
Total distributed earnings	107	99	309	294
Net income less distributed earnings	$ 120	$ 84	$ 220	$ 267
Distributed (dividends per common share)	$ 0.62	$ 0.59	$ 1.80	$ 1.74
Earnings Per Share, Diluted, Undistributed	$ 0.69	$ 0.48	$ 1.28	$ 1.56
Total Diluted Earnings per Common Share	$ 1.31	$ 1.07	$ 3.08	$ 3.30