Fair Value (Fair Value of Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	$ 35	$ 41
Dividends payable	124	122
Short-term borrowings	0	398
Long-term debt, excluding capital leases	8,989	8,606
Carrying Amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	6	12
Short-term borrowings	0	50
Long-term debt, excluding capital leases	5,643	5,259
Carrying Amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	8
Short-term borrowings	35	84
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Dividends payable	124	122
Short-term borrowings	0	0
Long-term debt, excluding capital leases	500	489
Fair Value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Long-term debt, excluding capital leases	0	0
Fair Value | Level 1 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Dividends payable	0	0
Short-term borrowings	0	398
Long-term debt, excluding capital leases	8,581	8,308
Fair Value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	50
Long-term debt, excluding capital leases	5,682	5,341
Fair Value | Level 2 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	35	41
Dividends payable	0	0
Short-term borrowings	0	0
Long-term debt, excluding capital leases	1,051	706
Fair Value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	6	12
Short-term borrowings	0	0
Long-term debt, excluding capital leases	735	496
Fair Value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	8
Short-term borrowings	$ 35	$ 84