Short-Term Credit Arrangements and Borrowings (Tables)

12 Months Ended

Dec. 31, 2018

Short-term Debt [Abstract]

Schedule of Line of Credit Facilities

The availability under the facilities in place at December 31, 2018 is shown in the following table:

	DTE Energy		DTE Electric		DTE Gas		Total
	(In millions)
Unsecured letter of credit facility, expiring in February 2019	$	150	$	—	$	—	$	150
Unsecured letter of credit facility, expiring in September 2019	70		—		—		70
Unsecured revolving credit facility, expiring April 2022	1,200		400		300		1,900
	1,420		400		300		2,120
Amounts outstanding at December 31, 2018
Commercial paper issuances	271		149		189		609
Letters of credit	168		—		—		168
	439		149		189		777
Net availability at December 31, 2018	$	981	$	251	$	111	$	1,343