Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Tax effect on benefit obligation	$ 2	$ 2	$ 3	$ 6
Tax effect Net Unrealized gains (losses) on investments	$ 1	$ 0	1	0
DTE Electric
Tax effect on benefit obligation - transfer			$ 0	$ 18