Property and Equipment, net (Detail Textuals) $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($)
Property Plant And Equipment [Abstract]
Property plant and equipment net increase due to ship improvement projects and ships under construction	$ 132.8

Amount of increase (decrease) of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentGrossPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration