Condensed Consolidated Statements Of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Operating Revenues	$ 494,422	$ 509,283	$ 992,307	$ 947,294
Costs and Expenses [Abstract]
Operating	403,210	409,365	787,322	751,108
Administrative and general	45,120	39,170	91,298	80,824
Depreciation and amortization	43,685	39,330	83,012	77,660
Total costs and expenses	492,015	487,865	961,632	909,592
Gains on Asset Dispositions and Impairments, Net	4,419	10,301	9,961	17,556
Operating Income	6,826	31,719	40,636	55,258
Other Income (Expense):
Interest income	7,641	3,297	10,617	7,029
Interest expense	(12,413)	(10,465)	(24,437)	(20,505)
Debt extinguishment losses, net	0	0	(160)	(48)
Marketable security gains, net	11,596	(4,754)	14,954	(3,220)
Derivative losses, net	3,487	(6,601)	(632)	(9,919)
Foreign currency gains, net	(992)	1,416	1,560	6,475
Other, net	443	(56)	389	(234)
Total Other Nonoperating Income (Expense)	9,762	(17,163)	2,291	(20,422)
Income from Continuing Operations Before Income Tax Expense and Equity in Earnings of 50% or Less Owned Companies	16,588	14,556	42,927	34,836
Income Tax Expense	5,975	5,877	16,583	13,550
Income from Continuing Operations Before Equity in Earnings of 50% or Less Owned Companies	10,613	8,679	26,344	21,286
Equity in Earnings of 50% or Less Owned Companies, Net of Tax	1,051	872	2,293	914
Income from Continuing Operations	11,664	9,551	28,637	22,200
Income (Loss) from Discontinued Operations, Net of Tax	(365)	(184)	19,035	(1,364)
Net Income	11,299	9,367	47,672	20,836
Net Income (Loss) attributable to Noncontrolling Interests in Subsidiaries	50	336	(65)	635
Net Income attributable to SEACOR Holdings Inc.	11,249	9,031	47,737	20,201
Net Income (Loss) attributable to SEACOR Holdings Inc.:
Continuing operations	11,614	9,215	28,702	21,565
Discontinued operations, net of tax	(365)	(184)	19,035	(1,364)
Net Income attributable to SEACOR Holdings Inc.	$ 11,249	$ 9,031	$ 47,737	$ 20,201
Basic Earnings Per Common Share of SEACOR Holdings Inc.
Continuing operations	$ 0.56	$ 0.44	$ 1.40	$ 1.02
Discontinued operations	$ (0.01)	$ (0.01)	$ 0.92	$ (0.06)
Earnings Per Share, Basic	$ 0.55	$ 0.43	$ 2.32	$ 0.96
Diluted Earnings Per Common Share of SEACOR Holdings Inc.
Continuing operations	$ 0.56	$ 0.43	$ 1.37	$ 1.00
Discontinued operations	$ (0.02)	$ (0.01)	$ 0.92	$ (0.06)
Earnings Per Share, Diluted	$ 0.54	$ 0.42	$ 2.29	$ 0.94
Weighted Average Common Shares Outstanding:
Basic	20,584,567	21,166,037	20,552,114	21,135,557
Diluted	20,871,380	21,517,725	20,883,570	21,478,759