Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable security gains (losses), net include losses	$ 700,000	$ 6,500,000	$ 5,700,000	$ 10,500,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	33,275,000		33,275,000
Derivative instruments (included in other receivables)	2,012,000		2,012,000
Construction reserve funds and Title XI reserve funds	324,856,000		324,856,000
Short sales of marketable securities	10,061,000		10,061,000
Derivative instruments (included in other current liabilities)	2,043,000		2,043,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0		0
Derivative instruments (included in other receivables)	4,442,000		4,442,000
Construction reserve funds and Title XI reserve funds	0		0
Short sales of marketable securities	0		0
Derivative instruments (included in other current liabilities)	1,016,000		1,016,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0		0
Derivative instruments (included in other receivables)	0		0
Construction reserve funds and Title XI reserve funds	0		0
Short sales of marketable securities	0		0
Derivative instruments (included in other current liabilities)	$ 0		$ 0