$ 1,566

$ 1,466

1,763

Estimated Fair Market Value, Total

1,745

Restricted cash

3,313

3,364

Cash, Cash Equivalents, and Short-Term Investments, Amortized Cost

3,331

3,380

U.S. government treasury securities

1,547

1,731

1,529

1,716

Corporate bonds

160

162

160

161

Commercial paper

U.S. government agency securities

Debt securities, available-for-sale, accumulated gross unrealized loss, before tax

Cash

Cash and Cash Equivalents, at Carrying Value [Abstract]

Cash and Cash Equivalents, at Carrying Value [Abstract]

128

Money market funds

Cash and Cash Equivalents, at Carrying Value [Abstract]

1,394

1,338

Commercial paper

$ 115

$ 0

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

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