Debt - Summary of Long-Term Debt (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt, gross	$ 10,307	$ 9,308
Unamortized premium and debt issue cost, net	82	60
Total debt	10,389	9,368
Less: current maturities	(2,954)	(1,409)
Total long-term debt	$ 7,435	7,959
2019 Unsecured Term Loan \| Term Loan
Debt Instrument [Line Items]
Maturity date	Feb. 28, 2020
Debt, gross	$ 700	0
2019 Unsecured Term Loan \| Term Loan \| Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	3.39%
Certificates \| Secured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2019
Maturity dates range, end	Dec. 31, 2027
Debt, gross	$ 2,276	1,837
Certificates \| Secured Debt \| Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	3.20%
Certificates \| Secured Debt \| Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	8.02%
Notes \| Secured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2019
Maturity dates range, end	Dec. 31, 2025
Debt, gross	$ 1,646	1,787
Notes \| Secured Debt \| Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	2.91%
Notes \| Secured Debt \| Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	6.46%
NYTDC Special Facilities Revenue Bonds, Series 2018 \| Bonds
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2022
Maturity dates range, end	Dec. 31, 2036
Debt, gross	$ 1,383	1,383
NYTDC Special Facilities Revenue Bonds, Series 2018 \| Bonds \| Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	4.00%
NYTDC Special Facilities Revenue Bonds, Series 2018 \| Bonds \| Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	5.00%
Unsecured notes \| Unsecured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2020
Maturity dates range, end	Dec. 31, 2028
Debt, gross	$ 4,050	4,050
Unsecured notes \| Unsecured Debt \| Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	2.60%
Unsecured notes \| Unsecured Debt \| Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	4.38%
Other financings \| Secured and Unsecured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2019
Maturity dates range, end	Dec. 31, 2030
Debt, gross	$ 252	251
Other financings \| Secured and Unsecured Debt \| Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	3.49%
Other financings \| Secured and Unsecured Debt \| Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	8.75%
2018 Unsecured Revolving Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2021
Maturity dates range, end	Dec. 31, 2023
Debt, gross	$ 0	0
Other revolving credit facilities \| Revolving Credit Facility
Debt Instrument [Line Items]
Maturity dates range, start	Jan. 01, 2019
Maturity dates range, end	Dec. 31, 2021
Debt, gross	$ 0	$ 0

Amount, before unamortized (discount) premium and 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.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

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Earliest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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