Retirement Benefits and Trusteed Assets (OPEB - Fair Value Measurements using Level 3 Inputs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	$ (129)	$ 40
Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	1,528	1,527
Total realized/unrealized gains (losses)	(25)	62
Plan assets at fair value, end of year	1,617	1,528
Other Postretirement Benefit Plan | Hedge Funds and Similar Investments
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	320
Plan assets at fair value, end of year	325	320
Other Postretirement Benefit Plan | Private Equity and Other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	131
Plan assets at fair value, end of year	153	131
Level 3 | Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	299	260
Total realized/unrealized gains (losses)	13	17
Purchases	45	42
Sales	(33)	(20)
Plan assets at fair value, end of year	324	299
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	3	15
Level 3 | Other Postretirement Benefit Plan | Hedge Funds and Similar Investments
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	168	159
Total realized/unrealized gains (losses)	4	8
Purchases	11	9
Sales	(12)	(8)
Plan assets at fair value, end of year	171	168
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	0	7
Level 3 | Other Postretirement Benefit Plan | Private Equity and Other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	131	101
Total realized/unrealized gains (losses)	9	9
Purchases	34	33
Sales	(21)	(12)
Plan assets at fair value, end of year	153	131
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	3	8
DTE Electric
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	3	3
DTE Electric | Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	1,038	1,061
Total realized/unrealized gains (losses)	(19)	41
Plan assets at fair value, end of year	1,131	1,038
DTE Electric | Other Postretirement Benefit Plan | Hedge Funds and Similar Investments
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	218
Plan assets at fair value, end of year	227	218
DTE Electric | Other Postretirement Benefit Plan | Private Equity and Other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	91
Plan assets at fair value, end of year	109	91
DTE Electric | Level 3 | Other Postretirement Benefit Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	205	182
Total realized/unrealized gains (losses)	9	11
Purchases	37	26
Sales	(23)	(14)
Plan assets at fair value, end of year	228	205
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	2	10
DTE Electric | Level 3 | Other Postretirement Benefit Plan | Hedge Funds and Similar Investments
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	114	111
Total realized/unrealized gains (losses)	3	5
Purchases	11	4
Sales	(9)	(6)
Plan assets at fair value, end of year	119	114
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	0	5
DTE Electric | Level 3 | Other Postretirement Benefit Plan | Private Equity and Other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	91	71
Total realized/unrealized gains (losses)	6	6
Purchases	26	22
Sales	(14)	(8)
Plan assets at fair value, end of year	109	91
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2015 and 2014 and reflected in Operating revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	$ 2	$ 5