Short-Term Credit Arrangements and Borrowings (Tables)

6 Months Ended

Jun. 30, 2018

Short-term Debt [Abstract]

Schedule of Line of Credit Facilities

The availability under the facilities in place at June 30, 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 June 30, 2018
Commercial paper issuances	177		130		167		474
Letters of credit	147		—		—		147
	324		130		167		621
Net availability at June 30, 2018	$	1,096	$	270	$	133	$	1,499