Basis Of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Basis Of Presentation [Abstract]
Minimum percentage of ownership considered for consolidation (in hundredths)			50.00%
Minimum percentage of ownership considered for equity method of accounting for investments (in hundredths)			20.00%
Maximum percentage of ownership considered for equity method of accounting for investments (in hundredths)			50.00%
Amortization expense for deferred charges - drydock		$ 4,500		$ 8,600
Miscellaneous depreciation expense	$ 187	$ 180	$ 371	$ 364