Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Useful Lives of Property and Equipment Used in Computation of Depreciation

Depreciation of property and equipment is computed utilizing the following useful lives:

	Years
Ships	generally 30
Ship improvements	3-20
Buildings and improvements	10-40
Computer hardware and software	3-10
Transportation equipment and other	3-30
Leasehold improvements	Shorter of remaining lease term or useful life 3-30

Passenger Ticket Revenues Attributed to Geographic Areas Based on Where Reservation Originates

Information by geographic area is shown in the table below. Passenger ticket revenues are attributed to geographic areas based on where the reservation originates.

	2016	2015	2014
Passenger ticket revenues:
United States	55%	55%	53%
All other countries	45%	45%	47%