Amount, after unamortized (discount) premium but before debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

No definition available.

Long-Term Debt (MIC Corporate) (Details)	1 Months Ended		12 Months Ended
Long-Term Debt (MIC Corporate) (Details)	Oct. 31, 2016 USD ($) $ / shares	Jul. 31, 2014 USD ($) $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 03, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Letters of credit			$ 13,000,000
Unamortized deferred financing costs			41,000,000	$ 50,000,000
Current and long-term debt			$ 2,707,000,000	3,064,000,000
Interest rate and fees, commitment fee percentage			0.35%
Revolving Credit Facility
Debt Instrument [Line Items]
Undrawn portion of line of credit			$ 1,610,000,000
MIC Corporate
Debt Instrument [Line Items]
Current and long-term debt			388,000,000	$ 734,000,000
MIC Corporate \| 2.875% Convertible Senior Notes due July 2019
Debt Instrument [Line Items]
Debt instrument, term		5 years
Interest rate		2.875%		2.875%
Convertible senior notes		$ 350,000,000		$ 350,000,000
Conversion rate		11.7942
Face value of convertible senior notes		$ 1,000
Conversion price \| $ / shares		$ 84.79
MIC Corporate \| 2.00% Convertible Senior Notes due October 2023
Debt Instrument [Line Items]
Debt instrument, term	7 years
Unamortized debt discount			$ 15,000,000
Interest rate	2.00%		2.00%	2.00%		2.00%
Convertible senior notes	$ 403,000,000
Conversion rate	8.9364		9.0290
Face value of convertible senior notes	$ 1,000		$ 1,000
Conversion price \| $ / shares	$ 111.90
Proceeds from convertible senior notes	$ 392,000,000
Interest rate, effective	3.10%
Equity component of Convertible senior notes	$ 27,000,000
Unamortized deferred financing costs	11,000,000
Issuance costs	1,000,000
Current and long-term debt	$ 376,000,000		388,000,000	$ 384,000,000
Convertible debt, fair value			370,000,000	335,000,000
MIC Corporate \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, term		5 years
Borrowing capacity		$ 250,000,000	$ 600,000,000	$ 600,000,000	$ 600,000,000	$ 410,000,000	$ 410,000,000
London Interbank Offered Rate (LIBOR) \| MIC Corporate \| Revolving Credit Facility
Debt Instrument [Line Items]
Fixed portion of interest rate component			2.00%
Minimum
Debt Instrument [Line Items]
Debt instrument, term			4 years
Maximum
Debt Instrument [Line Items]
Debt instrument, term			7 years