Significant Operations (Revenues Attributable To Major Geographic Areas) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues	$ 70,978	$ 74,410	$ 76,752	$ 72,694	$ 76,169	$ 77,938	$ 74,897	$ 81,124	$ 294,834	$ 310,128	$ 243,496
United States [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues									165,268	192,332	123,782
Asian Countries [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues									62,542	67,830	63,860
Rail-Ferry Service [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues									32,521	34,366	32,479
South America [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues										2,905	10,416
Europe [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues									10,449	6,966	12,474
Other Countries [Member]
Summary of revenues attributable to the major geographic areas [Abstract]
Total Revenues									$ 24,054	$ 5,729	$ 485