General form of registration statement for all companies including face-amount certificate companies

Employee Benefits and Share Option Plans - Additional information (Detail)

v2.4.0.8
Employee Benefits and Share Option Plans - Additional information (Detail) (USD $)
In Millions, except Per Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]      
Percentage of profit interest 2.70%    
IPO price per ordinary share $ 19.00    
Total share-based compensation expense recognized $ 0.7 $ 1.2 $ 2.5
Remaining liability under severance agreement 15.0    
Forfeited contributions utilized 0.1 0.2 0.2
Recorded expenses related to 401k plan and SERP 2.8 2.6 2.7
Discount rate used in the net periodic benefit cost calculation 4.70% 5.50% 6.00%
Amortization period of losses 18 years 10 months 10 days    
401(k) Plan
      
Defined Benefit Plan Disclosure [Line Items]      
Maximum percentage of employee eligible compensation that may be contributed towards 401(k) 100.00%    
Matching contributions vesting period 5 years    
401(k) Plan | The first 3%
      
Defined Benefit Plan Disclosure [Line Items]      
Employer matching contribution percent 100.00%    
Defined contribution plan, percentage of employee contribution 3.00%    
401(k) Plan | The next 4%-10%
      
Defined Benefit Plan Disclosure [Line Items]      
Employer matching contribution percent 50.00%    
401(k) Plan | The next 4%-10% | Minimum
      
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan, percentage of employee contribution 4.00%    
401(k) Plan | The next 4%-10% | Maximum
      
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan, percentage of employee contribution 10.00%    
Supplemental Executive Retirement Plan (SERP)
      
Defined Benefit Plan Disclosure [Line Items]      
Participants' deferred compensation accounts under the SERP Plan 0.4 0.7  
Shipboard Retirement Plan
      
Defined Benefit Plan Disclosure [Line Items]      
Projected benefit obligation included in accrued expenses and other liabilities 0.7 1.0  
Projected benefit obligation included in other long term liabilities 15.5 12.3  
TBUs
      
Defined Benefit Plan Disclosure [Line Items]      
Vesting period 5 years    
Aggregate fair value for profits interests 8.6    
Unrecognized share based compensation expense 0.6    
PBUs
      
Defined Benefit Plan Disclosure [Line Items]      
Aggregate fair value for profits interests $ 13.8