Acquisitions and Dispositions- Starwood Consideration Transferred (Details) - Starwood Hotels & Resorts Worldwide, Inc. $ / shares in Units, shares in Millions, $ in Millions	Sep. 23, 2016 USD ($) $ / shares shares
Business Acquisition [Line Items]
Equivalent shares of Marriott common stock issued in exchange for Starwood outstanding shares (in shares) | shares	134.4
Marriott common stock price as of Merger Date (in USD per share) | $ / shares	$ 68.44
Fair value of Marriott common stock issued in exchange for Starwood outstanding shares	$ 9,198
Cash consideration to Starwood shareholders, net of cash acquired of $1,116	2,412
Fair value of Marriott equity-based awards issued in exchange for vested Starwood equity-based awards	71
Total consideration transferred, net of cash acquired	11,681
Cash acquired	$ 1,116