Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company measures certain financial assets and liabilities at fair value. Fair value disclosures are reflected in a three-level hierarchy, maximizing the use of observable inputs and minimizing the use of unobservable inputs. The Company did not have any significant changes to the valuation techniques used to measure fair value as described in the Company's December 31, 2019 Annual Report on Form 10-K. At September 30, 2020, the fair value of the Company’s debt obligations was estimated at $43.4 billion, compared to a carrying amount of $37.8 billion, which reflects $5.5 billion of debt issuances during the first quarter under the Company's existing registration statement on Form S-3 with maturities ranging from 2025 to 2050 and interest rates ranging from 1.45% to 4.20%. The balances at September 30, 2020 also reflect the retirement of $900 million of commercial paper and $1.4 billion of other debt maturities compared with December 31, 2019. In addition, a $1 billion line of credit was entered into during the first quarter of 2020, and subsequently repaid in the third quarter. The fair value was based upon quoted market prices, Level 2 within the valuation hierarchy. The carrying amounts of cash and equivalents, short-term investments and notes receivable approximate fair value.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.