Aggregate Debt Maturities (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
2017	$ 562
2018	211
2020	500
2021	300
Thereafter	2,100
Debt principal outstanding	3,673
Deferred financing costs	(23)
Unamortized (discounts) premiums, net	(2)
Capital lease obligations	1
Total debt	$ 3,649	$ 3,867

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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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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Amount, after accumulated amortization, of debt discount (premium).

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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