Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Derivative [Line Items]
Derivative gains (losses), net	$ (3,896,000)	$ (35,725,000)
Options On Equities And Equity Indices [Member]
Derivative [Line Items]
Derivative gains (losses), net	(735,000)	2,725,000
Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	884,000	990,000
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Derivative gains (losses), net	(803,000)	(2,489,000)
Commodity Contract [Member]
Derivative [Line Items]
Derivative gains (losses), net	(4,743,000)	(8,818,000)
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]
Derivative [Line Items]
Derivative gains (losses), net	1,501,000	1,293,000
U.S. Treasury Notes, Rate Locks And Bond Future And Option Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	0	(29,426,000)
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Notional Amount of Foreign Currency Derivatives	18,200,000
SEACOR Holdings Inc. [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative, Lower Fixed Interest Rate Range	1.67%
Derivative, Higher Fixed Interest Rate Range	2.59%
Notional amount of interest rate derivatives	141,700,000
Offshore Marine Services Joint Ventures [Member]
Derivative [Line Items]
Notional amount of interest rate derivatives	$ 24,400,000
Offshore Marine Services Joint Ventures [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	3.05%