Reportable Segments (Narrative) (Details)	3 Months Ended
	Mar. 31, 2020 terminal airport segment facility
Segment Reporting Information [Line Items]
Number of reportable segments | segment	4
Canada- IMTT
Segment Reporting Information [Line Items]
Number of marine terminals	2
Canada- IMTT | Quebec Marine Terminal
Segment Reporting Information [Line Items]
Number of marine terminals	1
Canada- IMTT | Newfoundland Marine Terminal | Partially Owned
Segment Reporting Information [Line Items]
Number of marine terminals	1
IMTT
Segment Reporting Information [Line Items]
Number of marine terminals	17
Atlantic Aviation
Segment Reporting Information [Line Items]
Number of airport locations | airport	70
MIC Hawaii
Segment Reporting Information [Line Items]
Number of solar projects | facility	2
MIC Hawaii | Minimum
Segment Reporting Information [Line Items]
Life of purchase power agreements	20 years