CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income		$ 9	$ 36	$ 78	$ 83
Other comprehensive income (loss), net of taxes:
Translation adjustment	[1]	2	(2)	2	(3)
Other comprehensive income (loss)		2	(2)	2	(3)
Comprehensive income		11	34	80	80
Less: comprehensive loss attributable to noncontrolling interests		(2)	(2)	(3)	(32)
Comprehensive income attributable to MIC		$ 13	$ 36	$ 83	$ 112

[1] Translation adjustment is presented net of tax expense of $1 million for the quarter and six months ended June 30, 2019. For the quarter and six months ended June 30, 2018, translation adjustment is presented net of tax benefit of $1 million.