CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
OPERATING ACTIVITIES
Net income	$ 207us-gaap_NetIncomeLoss	$ 172us-gaap_NetIncomeLoss
Adjustments to reconcile to cash provided by operating activities:
Depreciation, amortization, and other	44	36
Share-based compensation	24us-gaap_ShareBasedCompensation	25us-gaap_ShareBasedCompensation
Income taxes	29mar_NoncashIncomeTaxExpense	16mar_NoncashIncomeTaxExpense
Liability for guest loyalty programs	45	30
Working capital changes	(131)	(121)
Other	44	24
Net cash provided by operating activities	262	182
INVESTING ACTIVITIES
Capital expenditures	(75)	(61)
Dispositions	247	292
Loan advances	(10)mar_PaymentsForLoanAdvances	(3)mar_PaymentsForLoanAdvances
Loan collections	7	9
Equity and cost method investments	(1)	(1)
Contract acquisition costs	(61)	(6)
Escrow deposit for acquisition of a business	(136)	(192)
Other	7	4
Net cash (used in) provided by investing activities	(22)	42
FINANCING ACTIVITIES
Commercial paper/Credit Facility, net	246	149
Repayment of long-term debt	(2)us-gaap_RepaymentsOfLongTermDebt	(2)us-gaap_RepaymentsOfLongTermDebt
Issuance of Class A Common Stock	17	57
Dividends paid	(56)us-gaap_PaymentsOfDividendsCommonStock	(50)us-gaap_PaymentsOfDividendsCommonStock
Purchase of treasury stock	(429)	(320)
Net cash used in financing activities	(224)	(166)
INCREASE IN CASH AND EQUIVALENTS	16	58
CASH AND EQUIVALENTS, beginning of period	104	126
CASH AND EQUIVALENTS, end of period	$ 120	$ 184

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The non-cash component of income tax expense, less the tax benefit from exercise of stock options.

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The cash outflow from advancing money to others in the form of loans.

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The net cash inflow (outflow) from issuing (borrowing) and repaying commercial paper or line of credit having initial term of repayment greater than one year or the normal operating cycle, if longer.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.

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Increase (decrease) in the liability arising from revenue deferred or cost to provide future products or services resulting from customer loyalty program. Excludes liability associated with frequent flier programs. Includes liability associated with customer loyalty programs for other businesses, for example, but not limited to, hotels, supermarkets, credit card companies, automobile rental companies, and book sellers.

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The increase (decrease) during the reporting period in other assets used in operating activities less other operating liabilities used in operating activities not separately disclosed in the statement of cash flows. May include changes in other current assets and liabilities, other noncurrent assets and liabilities, or a combination of other current and noncurrent assets and liabilities.

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Other cash or noncash adjustments to reconcile net income to cash provided by (used in) operating activities that are not separately disclosed in the statement of cash flows (for example, cash received or cash paid during the current period for miscellaneous operating activities, net change during the reporting period in other assets or other liabilities).

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The cash outflow associated with other payments to acquire businesses including deposit on pending acquisitions and preacquisition costs.

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The net cash outflow or inflow from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.

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The cash outflow to reacquire common stock during the period.

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill.

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The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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The cash inflow from the additional capital contribution to the entity.

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The cash inflow associated with the proceeds from sale of notes receivable, as well as principal collections from a borrowing supported by a written promise to pay an obligation (note receivable).

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The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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