Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount		$ 11,100
Tax Adjustments, Settlements, and Unusual Provisions	$ 0
Current
Federal		(47)	$ 0	$ (1,632)
State		688	836	1,330
Foreign		1,386	999	806
Total current		2,027	1,835	504
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal		0	0	(847)
State		19	(8)	(354)
Foreign		738	38	596
Total deferred		757	30	(605)
Total tax provision (benefit)		2,784	1,865	(101)
Effective income tax rate reconciliation (table)
Income tax provision (benefit) computed at statutory federal income tax rates		(12,809)	(46,332)	(49,888)
Partnership earnings		12,809	46,332	49,888
Corporate subsidiary earnings (loss) subject to federal tax		5,805	(33,791)	(36,712)
Impact of goodwill impairments		0	2,134	3,341
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount		21,928	0	0
Valuation allowances		(28,236)	33,056	33,682
Income tax expense attributable to foreign earnings		2,565	1,297	92
State income taxes (net of federal benefit)		734	(849)	(619)
Nondeductible expenses		36	23	79
Other		(48)	(5)	36
Total tax provision (benefit)		2,784	1,865	(101)
Income before income tax (table)
Domestic		(40,649)	(146,007)	(150,814)
International		2,974	9,734	4,083
Total		(37,675)	(136,273)	(146,731)
Deferred tax assets
Inventory reserve	270	270	690
Excess tax over book basis in long-lived assets	27,721	27,721	46,487
Accruals	264	264	452
Net operating losses	17,809	17,809	33,300
Bad debt reserve	144	144	472
Other	42	42	84
Total deferred tax assets	46,250	46,250	81,485
Valuation allowance	(39,367)	(39,367)	(69,176)
Net deferred tax assets	6,883	6,883	12,309
Deferred tax liabilities
Accruals	1,076	1,076	269
Deferred Tax Liabilities, Property, Plant and Equipment	7,011	7,011	11,892
All other	190	190	838
Total deferred tax liability	8,277	8,277	12,999
Net deferred tax lilability	1,394	1,394	690
Foreign net operating loss carryforwards / carrybacks	15,400	15,400
Operating Loss Carryforwards	1,500	1,500
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	$ 900	900
Increase in valuation allowance		$ 29,800	$ 33,000	$ 34,100
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	35.00%