Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 81	$ 227	$ 146	$ 156	$ 150	$ 183	$ 202	$ 176	$ 610	$ 711	$ 630
Average number of common shares outstanding									171	169	168
Weighted average net restricted shares outstanding									1	1	1
Dividends declared - common shares									413	392	365
Dividends declared - net restricted shares									1	1	2
Total distributed earnings									414	393	367
Net income less distributed earnings									196	318	263
Distributed (dividends per common share)									$ 2.42	$ 2.32	$ 2.18
Undistributed									$ 1.14	$ 1.87	$ 1.57
Total Basic Earnings per Common Share	$ 0.47	$ 1.32	$ 0.86	$ 0.91	$ 0.88	$ 1.08	$ 1.19	$ 1.04	$ 3.56	$ 4.19	$ 3.75
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	81	227	146	156	150	183	202	176	610	711	630
Average number of common shares outstanding									171	169	168
Average incremental shares from assumed exercise of options									1	1	1
Common shares for dilutive calculation									172	170	169
Weighted average net restricted shares outstanding									1	1	1
Dividends declared - common shares									413	392	365
Dividends declared - net restricted shares									1	1	2
Total distributed earnings									414	393	367
Net income less distributed earnings									$ 196	$ 318	$ 263
Distributed (dividends per common share)									$ 2.42	$ 2.32	$ 2.18
Earnings Per Share, Diluted, Undistributed									$ 1.13	$ 1.86	$ 1.56
Total Diluted Earnings per Common Share	$ 0	$ 1.31	$ 0.86	$ 0.91	$ 0.88	$ 1.07	$ 1.19	$ 1.04	$ 3.55	$ 4.18	$ 3.74