Condensed Consolidated Statements Of Income (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
Operating Revenues	$ 315,563	$ 309,225	$ 582,627	$ 607,074
Costs and Expenses [Abstract]
Operating	240,113	244,545	441,026	452,964
Administrative and general	34,718	36,301	70,363	71,292
Depreciation and amortization	33,783	33,220	67,331	62,922
Total costs and expenses	308,614	314,066	578,720	587,178
Gain (Loss) on Sale of Assets and Asset Impairment Charges	12,305	3,342	14,320	7,119
Operating Income (Loss)	19,254	(1,499)	18,227	27,015
Other Income (Expense):
Interest income	3,218	7,392	6,385	10,035
Interest expense	(7,922)	(10,012)	(20,762)	(19,999)
Debt extinguishment losses, net	0	0	0	(160)
Marketable security gains, net	6,557	11,596	10,552	14,954
Derivative losses, net	(825)	2,554	(2,932)	(404)
Foreign currency gains, net	(916)	(1,024)	(4,927)	637
Other, net	195	443	198	359
Total Other Nonoperating Income (Expense)	307	10,949	(11,486)	5,422
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	19,561	9,450	6,741	32,437
Income Tax Expense (Benefit)	7,975	3,250	5,322	12,710
Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	11,586	6,200	1,419	19,727
Equity in Earnings (Losses) of 50% or Less Owned Companies, Net of Tax	(7,710)	(295)	(6,841)	(7,956)
Income from Continuing Operations	19,296	6,495	8,260	27,683
Income (Loss) from Discontinued Operations, Net of Tax	0	4,804	(211)	19,989
Net Income	19,296	11,299	8,049	47,672
Net Income (Loss) Attributable to Noncontrolling Interest	25	50	(348)	(65)
Net Income attributable to SEACOR Holdings Inc.	19,271	11,249	8,397	47,737
Net Income (Loss) attributable to SEACOR Holdings Inc.:
Continuing operations	19,271	6,445	8,508	27,748
Discontinued operations, net of tax	0	4,804	(111)	19,989
Net Income attributable to SEACOR Holdings Inc.	$ 19,271	$ 11,249	$ 8,397	$ 47,737
Basic Earnings Per Common Share of SEACOR Holdings Inc.
Continuing operations	$ 0.97	$ 0.31	$ 0.43	$ 1.35
Discontinued operations	$ 0.00	$ 0.24	$ (0.01)	$ 0.97
Earnings Per Share, Basic	$ 0.97	$ 0.55	$ 0.42	$ 2.32
Diluted Earnings Per Common Share of SEACOR Holdings Inc.
Continuing operations	$ 0.91	$ 0.31	$ 0.42	$ 1.33
Discontinued operations	$ 0.00	$ 0.23	$ 0.00	$ 0.96
Earnings Per Share, Diluted	$ 0.91	$ 0.54	$ 0.42	$ 2.29
Weighted Average Common Shares Outstanding:
Basic	19,825,229	20,584,567	19,782,318	20,552,114
Weighted Average Number of Shares Outstanding, Diluted	24,392,312	20,871,380	20,114,904	20,883,570