Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net Income	$ 1,112	$ 834	$ 720
Net Income	1,134	868	727
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	1,030	976	852
Nuclear fuel amortization	53	58	46
Allowance for equity funds used during construction	(23)	(21)	(21)
Deferred income taxes	196	265	237
Equity earnings of equity method investees	(102)	(68)	(66)
Dividends from equity method investees	74	68	64
Asset (gains) losses and impairments, net	38	8	107
Changes in assets and liabilities:
Accounts receivable, net	(252)	(226)	259
Inventories	(4)	37	1
Accounts payable	129	145	(158)
Accrued pension liability	(228)	19	(147)
Accrued postretirement liability	25	(192)	(287)
Derivative assets and liabilities	(94)	126	47
Regulatory assets and liabilities	217	(40)	85
Other current and noncurrent assets and liabilities	(54)	95	177
Net cash from operating activities	2,117	2,084	1,916
Investing Activities
Plant and equipment expenditures — utility	(2,037)	(1,898)	(1,817)
Plant and equipment expenditures — non-utility	(213)	(147)	(203)
Acquisition, net of cash acquired	0	(1,147)	(241)
Restricted cash for debt redemption, principally Securitization, net	(2)	1	97
Proceeds from sale of nuclear decommissioning trust fund assets	1,240	1,457	885
Investment in nuclear decommissioning trust funds	(1,226)	(1,463)	(898)
Distributions from equity method investees	10	11	19
Contributions to equity method investees	(299)	(239)	(98)
Other	(37)	37	52
Net cash used for investing activities	(2,564)	(3,388)	(2,204)
Financing Activities
Issuance of long-term debt, net of issuance costs	1,398	2,035	956
Redemption of long-term debt	(385)	(807)	(286)
Repurchase of long-term debt	0	(59)	0
Issuance of equity units, net of issuance costs	0	654	0
Short-term borrowings, net	122	0	101
Repurchase of common stock	(51)	(33)	0
Dividends on common stock	(592)	(531)	(501)
Contributions from noncontrolling interests	50	114	23
Distributions to noncontrolling interests	(40)	(5)	(8)
Other	(81)	(9)	(8)
Net cash from (used for) financing activities	421	1,359	277
Net Increase (Decrease) in Cash and Cash Equivalents	(26)	55	(11)
Cash and Cash Equivalents at Beginning of Period	92	37	48
Cash and Cash Equivalents at End of Period	66	92	37
Supplemental disclosure of cash information
Cash paid (received) for: Interest, net of interest capitalized	495	448	428
Cash paid (received) for: Income taxes	4	(1)	14
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Plant and equipment expenditures in accounts payable	295	312	207
Premium on equity units	0	98	0
DTE Electric
Operating Activities
Net Income	601	622	544
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	753	750	633
Nuclear fuel amortization	53	58	46
Allowance for equity funds used during construction	(18)	(18)	(20)
Deferred income taxes	345	342	320
Equity earnings of equity method investees	(1)	(2)	(2)
Changes in assets and liabilities:
Accounts receivable, net	(80)	(64)	33
Inventories	31	26	(22)
Prepaid postretirement benefit costs — affiliates	1	(90)	(24)
Accounts payable	(2)	59	(46)
Accrued pension liability — affiliates	(197)	32	(224)
Accrued postretirement liability — affiliates	42	(38)	(213)
Regulatory assets and liabilities	202	10	65
Other current and noncurrent assets and liabilities	(147)	(34)	58
Net cash from operating activities	1,584	1,655	1,150
Investing Activities
Plant and equipment expenditures	(1,574)	(1,503)	(1,545)
Acquisitions	0	0	(310)
Restricted cash for debt redemption, principally Securitization, net	0	0	96
Proceeds from sale of nuclear decommissioning trust fund assets	1,240	1,457	885
Investment in nuclear decommissioning trust funds	(1,226)	(1,463)	(898)
Transfer of Rabbi Trust assets to affiliate	0	0	137
Other	18	36	14
Net cash used for investing activities	(1,542)	(1,473)	(1,621)
Financing Activities
Issuance of long-term debt, net of issuance costs	435	355	495
Redemption of long-term debt	(300)	(10)	(135)
Repurchase of long-term debt	0	(59)	0
Capital contribution by parent company	100	120	300
Short-term borrowings, net — affiliate	(1)	41	(8)
Short-term borrowings, net — other	176	(210)	222
Dividends on common stock	(432)	(420)	(395)
Other	(18)	(1)	(7)
Net cash from (used for) financing activities	(40)	(184)	472
Net Increase (Decrease) in Cash and Cash Equivalents	2	(2)	1
Cash and Cash Equivalents at Beginning of Period	13	15	14
Cash and Cash Equivalents at End of Period	15	13	15
Supplemental disclosure of cash information
Cash paid (received) for: Interest, net of interest capitalized	252	252	244
Cash paid (received) for: Income taxes	(16)	6	(53)
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Plant and equipment expenditures in accounts payable	$ 191	$ 232	$ 150