Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Derivative [Line Items]
Derivative gains (losses), net	$ (2,932,000)	$ (385,000)
Options On Equities And Equity Indices [Member]
Derivative [Line Items]
Derivative gains (losses), net	(3,012,000)	(910,000)
Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	(592,000)	373,000
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Derivative gains (losses), net	237,000	(237,000)
Commodity Contract [Member]
Derivative [Line Items]
Derivative gains (losses), net	(821,000)	(1,863,000)
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]
Derivative [Line Items]
Derivative gains (losses), net	1,256,000	2,252,000
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	13,100,000
SEACOR Holdings Inc. [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Lower Fixed Interest Rate Range	2.25%
Derivative, Higher Fixed Interest Rate Range	3.05%
Offshore Marine Services Joint Ventures [Member]
Derivative [Line Items]
Derivative, Notional Amount	17,500,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 221,100,000