Reportable Segments (Schedule of EBITDA for Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net income (loss)	$ 15	$ 2	$ 85	$ 69
Interest expense, net	34	28	118	71
Provision (benefit) for income taxes	7	2	33	32
Goodwill impairment	0	3	0	3
Depreciation	49	49	145	143
Amortization of intangibles	14	20	44	53
Fees to Manager-related party	8	12	23	36
Other non-cash expense	6	7	19	18
EBITDA excluding non-cash items	133	123	467	425
IMTT
Segment Reporting Information [Line Items]
Net income (loss)	12	16	62	60
Interest expense, net	10	12	38	31
Provision (benefit) for income taxes	5	6	25	24
Goodwill impairment		0		0
Depreciation	29	29	87	87
Amortization of intangibles	3	4	11	12
Fees to Manager-related party	0	0	0	0
Other non-cash expense	3	2	7	7
EBITDA excluding non-cash items	62	69	230	221
Atlantic Aviation
Segment Reporting Information [Line Items]
Net income (loss)	14	25	48	78
Interest expense, net	18	5	59	9
Provision (benefit) for income taxes	5	9	18	29
Goodwill impairment		0		0
Depreciation	16	14	46	43
Amortization of intangibles	11	12	33	35
Fees to Manager-related party	0	0	0	0
Other non-cash expense	0	0	1	1
EBITDA excluding non-cash items	64	65	205	195
MIC Hawaii
Segment Reporting Information [Line Items]
Net income (loss)	1	(18)	11	(11)
Interest expense, net	3	2	8	5
Provision (benefit) for income taxes	1	(7)	5	(4)
Goodwill impairment		3		3
Depreciation	4	6	12	13
Amortization of intangibles	0	4	0	6
Fees to Manager-related party	0	0	0	0
Other non-cash expense	3	5	10	10
EBITDA excluding non-cash items	12	(5)	46	22
Corporate and Other
Segment Reporting Information [Line Items]
Net income (loss)	(12)	(21)	(36)	(58)
Interest expense, net	3	9	13	26
Provision (benefit) for income taxes	(4)	(6)	(15)	(17)
Goodwill impairment		0		0
Depreciation	0	0	0	0
Amortization of intangibles	0	0	0	0
Fees to Manager-related party	8	12	23	36
Other non-cash expense	0	0	1	0
EBITDA excluding non-cash items	$ (5)	$ (6)	$ (14)	$ (13)