Income per Share (Schedule of Reconciliation of the basic and diluted income (loss) per share computations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net (loss) income from continuing operations attributable to MIC	$ (8)	$ 6	$ 3	$ 70
Diluted net (loss) income from continuing operations attributable to MIC	(8)	6	3	70
Basic and diluted net income from discontinued operations attributable to MIC	$ 0	$ 5	$ 0	$ 11
Denominator:
Weighted average number of shares outstanding: basic (in shares)	86,871,892	86,073,372	86,779,432	85,973,308
Dilutive effect of restricted stock unit grants (in shares)	0	25,739	59,087	24,698
Weighted average number of shares outstanding: diluted (in shares)	86,871,892	86,099,111	86,838,519	85,998,006
Income per share:
Basic (loss) income per share from continuing operations attributable to MIC (in dollars per share)	$ (0.09)	$ 0.07	$ 0.04	$ 0.81
Basic income per share from discontinued operations attributable to MIC (in dollars per share)	0	0.06	0	0.13
Basic (loss) income per share attributable to MIC (in dollars per share)	(0.09)	0.13	0.04	0.94
Diluted (loss) income per share from continuing operations attributable to MIC (in dollars per share)	(0.09)	0.07	0.04	0.81
Diluted income per share from discontinued operations attributable to MIC (in dollars per share)	0	0.06	0	0.13
Diluted (loss) income per share attributable to MIC (in dollars per share)	$ (0.09)	$ 0.13	$ 0.04	$ 0.94