Significant Accounting Policics (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (155)	$ (136)
Other comprehensive income (loss) before reclassifications	(1)	(26)
Amounts reclassified from Accumulated other comprehensive income	11	7
Net current-period Other comprehensive income (loss)	10	(19)	$ 22
Ending balance	(145)	(155)	(136)
Net Unrealized Loss on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(4)	(4)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from Accumulated other comprehensive income	0	0
Net current-period Other comprehensive income (loss)	0	0
Ending balance	(4)	(4)	(4)
Net Unrealized Gain/(Loss) on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(5)	(6)
Other comprehensive income (loss) before reclassifications	1	1
Amounts reclassified from Accumulated other comprehensive income	0	0
Net current-period Other comprehensive income (loss)	1	1
Ending balance	(4)	(5)	(6)
Benefit Obligations (b)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(144)	(126)
Other comprehensive income (loss) before reclassifications	2	(25)
Amounts reclassified from Accumulated other comprehensive income	11	7
Net current-period Other comprehensive income (loss)	13	(18)
Ending balance	(131)	(144)	(126)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2)	0
Other comprehensive income (loss) before reclassifications	(4)	(2)
Amounts reclassified from Accumulated other comprehensive income	0	0
Net current-period Other comprehensive income (loss)	(4)	(2)
Ending balance	(6)	(2)	0
DTE Electric
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(26)	(16)
Other comprehensive income (loss) before reclassifications	1	(12)
Transfer of amounts from Accumulated other comprehensive income to affiliate	27
Amounts reclassified from Accumulated other comprehensive income	0	2
Net current-period Other comprehensive income (loss)	28	(10)	6
Ending balance	2	(26)	(16)
DTE Electric | Net Unrealized Gain/(Loss) on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	1	1
Other comprehensive income (loss) before reclassifications	1	0
Transfer of amounts from Accumulated other comprehensive income to affiliate	0
Amounts reclassified from Accumulated other comprehensive income	0	0
Net current-period Other comprehensive income (loss)	1	0
Ending balance	2	1	1
DTE Electric | Benefit Obligations (b)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(27)	(17)
Other comprehensive income (loss) before reclassifications	0	(12)
Transfer of amounts from Accumulated other comprehensive income to affiliate	27
Amounts reclassified from Accumulated other comprehensive income	0	2
Net current-period Other comprehensive income (loss)	27	(10)
Ending balance	$ 0	$ (27)	$ (17)