Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

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