CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Passenger ticket revenues	$ 1,425,644	$ 1,418,223
Onboard and other revenues	602,112	590,337
Total revenues	2,027,756	2,008,560
Cruise operating expenses:
Commissions, transportation and other	290,609	310,248
Onboard and other	99,537	105,994
Payroll and related	227,156	215,735
Food	119,642	121,211
Fuel	160,341	177,414
Other operating	278,734	245,222
Total cruise operating expenses	1,176,019	1,175,824
Marketing, selling and administrative expenses	337,361	317,465
Depreciation and amortization expenses	240,230	235,749
Operating Income	274,146	279,522
Other income (expense):
Interest income	7,733	6,252
Interest expense, net of interest capitalized	(67,878)	(80,317)
Equity investment income	28,752	11,880
Impairment loss related to Skysea Holding	23,343	0
Other expense	(757)	(2,611)
Total other income (expense)	(55,493)	(64,796)
Net Income	$ 218,653	$ 214,726
Earnings per Share:
Basic (in dollars per share)	$ 1.03	$ 1.00
Diluted (in dollars per share)	$ 1.02	$ 0.99
Weighted-Average Shares Outstanding:
Basic (in shares)	212,610	214,870
Diluted (in shares)	213,602	215,813
Comprehensive Income
Net Income	$ 218,653	$ 214,726
Other comprehensive income (loss):
Foreign currency translation adjustments	1,160	2,342
Change in defined benefit plans	7,760	(641)
Gain on cash flow derivative hedges	142,530	22,461
Total other comprehensive income	151,450	24,162
Comprehensive Income	$ 370,103	$ 238,888