Earnings Per Common Share of SEACOR (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Net Income (Loss) Attributable to Parent	$ 19,271	$ 11,249	$ (1,717)	$ 47,737
Net Income (Loss) Available to Common Stockholders, Diluted	22,315	11,249	(1,717)	47,737
Weighted Average Number of Shares Outstanding, Basic	19,825,229	20,584,567	19,782,318	20,552,114
Incremental Common Shares Attributable to Share-based Payment Arrangements	366,558	286,813	332,586	331,456
Incremental Common Shares Attributable to Conversion of Debt Securities	4,200,525		0
Weighted Average Number of Shares Outstanding, Diluted	24,392,312	20,871,380	20,114,904	20,883,570
Earnings Per Share, Basic	$ 0.97	$ 0.55	$ (0.09)	$ 2.32
Earnings Per Share, Diluted	$ 0.91	$ 0.54	$ (0.09)	$ 2.29
Outstanding Stock Awards [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	355,490	593,344	503,726	531,101
Two Point Five Percentage Convertible Notes [Domain]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			4,200,525
Equity Securities [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Dilutive Securities, Effect on Basic Earnings Per Share	0	0	0	0
Convertible Debt Securities [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Dilutive Securities, Effect on Basic Earnings Per Share	$ 3,044		$ 0
Two Point Five Percentage Convertible Notes [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.50%		2.50%