CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Total revenues	$ 2,337,605	$ 2,195,274	$ 4,365,361	$ 4,203,834
Cruise operating expenses:
Total cruise operating expenses	1,314,411	1,256,785	2,490,430	2,432,609
Marketing, selling and administrative expenses	312,923	283,855	650,284	601,320
Depreciation and amortization expenses	253,376	234,937	493,606	470,686
Operating Income	456,895	419,697	731,041	699,219
Other income (expense):
Interest income	13,098	5,811	20,831	12,063
Interest expense, net of interest capitalized	(81,864)	(76,632)	(149,742)	(156,949)
Equity investment income	44,311	23,359	73,063	35,239
Other income (expense)	33,855	(2,709)	9,755	(5,320)
Total other income (expense)	9,400	(50,171)	(46,093)	(114,967)
Net Income	$ 466,295	$ 369,526	$ 684,948	$ 584,252
Earnings per Share:
Basic (in dollars per share)	$ 2.20	$ 1.72	$ 3.23	$ 2.72
Diluted (in dollars per share)	$ 2.19	$ 1.71	$ 3.21	$ 2.71
Weighted-Average Shares Outstanding:
Basic (in shares)	211,673	215,085	212,139	214,978
Diluted (in shares)	212,509	216,062	213,079	215,944
Comprehensive Income
Net Income	$ 466,295	$ 369,526	$ 684,948	$ 584,252
Other comprehensive income (loss):
Foreign currency translation adjustments	(11,521)	5,979	(10,361)	8,321
Change in defined benefit plans	(1,964)	(3,649)	5,796	(4,290)
(Loss) gain on cash flow derivative hedges	(68,900)	128,954	73,630	151,415
Total other comprehensive (loss) income	(82,385)	131,284	69,065	155,446
Comprehensive Income	383,910	500,810	754,013	739,698
Passenger ticket revenues
Total revenues	1,672,570	1,581,385	3,098,214	2,999,608
Onboard and other revenues
Total revenues	665,035	613,889	1,267,147	1,204,226
Cruise operating expenses:
Total cruise operating expenses	142,240	132,437	241,777	238,431
Commissions, transportation and other
Cruise operating expenses:
Total cruise operating expenses	358,305	340,331	648,914	650,579
Payroll and related
Cruise operating expenses:
Total cruise operating expenses	226,315	210,362	453,471	426,097
Food
Cruise operating expenses:
Total cruise operating expenses	128,383	121,764	248,025	242,975
Fuel
Cruise operating expenses:
Total cruise operating expenses	172,309	170,748	332,650	348,162
Other operating
Cruise operating expenses:
Total cruise operating expenses	$ 286,859	$ 281,143	$ 565,593	$ 526,365