Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Costs and Expenses [Abstract]
Total costs and expenses	$ 112,695	$ 100,431	$ 227,504	$ 201,241
Gains (Losses) on Asset Dispositions and Impairments, Net	5,897	2,586	5,709	3,183
Net Income (Loss)	(28,629)	(27,169)	(34,077)	(37,417)
Offshore Marine Services [Member]
Operating Revenues	27,987	57,271	62,291	117,150
Costs and Expenses [Abstract]
Operating	32,509	44,245	65,888	93,095
Administrative and general	17,856	11,929	29,682	24,327
Depreciation and amortization	9,678	15,254	22,181	30,092
Total costs and expenses	60,043	71,428	117,751	147,514
Operating Income (Loss)	(32,656)	(34,514)	(51,241)	(51,101)
Other Income (Expense), Net	(5,346)	(6,702)	1,780	(11,682)
Income Tax Expense (Benefit)	(9,509)	(13,742)	(12,931)	(20,568)
Equity in Earnings (Losses) of 50% or Less Owned Companies	1,225	(3,315)	1,663	(1,154)
Net Income (Loss)	(27,268)	(30,789)	(34,867)	(43,369)
Net Income (Loss) Attributable to Noncontrolling Interests	(1,688)	(209)	(1,892)	(831)
Illinois Corn Processing LLC [Member]
Operating Revenues	39,676	40,576	78,061	90,185
Costs and Expenses [Abstract]
Operating	40,205	36,153	76,306	82,442
Administrative and general	1,363	912	2,109	1,568
Depreciation and amortization	1,179	1,064	2,354	2,117
Total costs and expenses	42,747	38,129	80,769	86,127
Operating Income (Loss)	(3,071)	2,447	(2,708)	4,058
Other Income (Expense), Net	487	1,791	2,335	2,477
Income Tax Expense (Benefit)	(668)	1,267	67	1,982
Net Income (Loss)	(1,916)	2,971	(440)	4,553
Net Income (Loss) Attributable to Noncontrolling Interests	(915)	984	(539)	1,406
Intersegment Eliminations [Member]
Operating Revenues	(520)	(456)	(1,176)	(1,068)
Costs and Expenses [Abstract]
Operating	(561)	(543)	(1,289)	(1,250)
Administrative and general	(19)	(27)	(42)	(53)
Total costs and expenses	(580)	(570)	(1,331)	(1,303)
Operating Income (Loss)	60	114	155	235
Other Income (Expense), Net	795	884	1,738	1,917
Income Tax Expense (Benefit)	300	349	663	753
Net Income (Loss)	555	649	1,230	1,399
Offshore Marine Services [Member] | Offshore Marine Services [Member]
Costs and Expenses [Abstract]
Gains (Losses) on Asset Dispositions and Impairments, Net	$ (600)	$ (20,357)	$ 4,219	$ (20,737)