Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal			$ 0	$ (651)	$ 0
State			1,465	799	783
Foreign			5,430	3,943	3,181
Total current			6,895	4,091	3,964
Deferred
Federal			(79)	394	0
State			(153)	(648)	(610)
Foreign			(364)	(3,086)	(1,198)
Total deferred			(596)	(3,340)	(1,808)
Provision (benefit) for income taxes			6,299	751	2,156
Effective Income Tax Rate Reconciliation Detail [Table]
Income tax provision (benefit) computed at statutory federal income tax rates			(7,650)	(15,415)	(78,128)
State income taxes (net of federal benefit)			55	1,664	(2,960)
Impact of international operations			14,477	10,847	7,556
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount		$ 54,100	(2,510)	55,813	0
Goodwill impairments			0	0	12,990
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Amount			5,204	5,151	2,247
Valuation allowance			(7,443)	(63,635)	53,918
Other			4,166	6,326	6,533
Provision (benefit) for income taxes			6,299	751	2,156
Domestic and Foreign Income Before Tax Detail [Table]
Domestic			(44,957)	(29,419)	(221,609)
International			8,531	(14,624)	(1,611)
Total			(36,426)	(44,043)	(223,220)
Unrecognized Tax Benefit Liability Rollforward Detail [Table]
Gross unrecognized tax benefits at beginning of period			530	857	1,219
Decreases in tax positions for prior years			0	0	0
Increases in tax positions for current year			0	0	16
Lapse in statute of limitations			(202)	(327)	(378)
Gross unrecognized tax benefits at end of period	$ 328	530	328	530	857
Recognized interest and penalties			(200)	(300)	(200)
Accrued potential interest and penalties	500	700	500	700
Amount of unrecognized tax benefits that would affect effective tax rate	800	1,100	800	1,100
Deferred tax assets:
Net operating losses	100,910	88,025	100,910	88,025
Foreign tax credits and alternative minimum tax credits	3,441	19,346	3,441	19,346
Accruals	9,396	24,577	9,396	24,577
Deferred Tax Assets, Tax Credit Carryforwards, Amortization for book in excess of tax expense	35,242	40,979	35,242	40,979
All other	11,140	3,813	11,140	3,813
Total deferred tax assets	160,129	176,740	160,129	176,740
Valuation allowance	(129,034)	(130,453)	(129,034)	(130,453)
Net deferred tax assets	31,095	46,287	31,095	46,287
Deferred tax liabilities:
Excess book over tax basis in property, plant, and equipment	31,999	48,618	31,999	48,618
All other	2,325	2,064	2,325	2,064
Total deferred tax liability	34,324	50,682	34,324	50,682
Net deferred tax liability	3,229	$ 4,395	3,229	4,395
Increase (decrease) in valuation allowance			(1,400)	$ (54,800)	$ 58,600
Foreign and state net operating loss carryforwards	75,300		75,300
Operating Loss Carryforwards	11,100		11,100
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	14,500		14,500
Foreign tax credits	2,900		$ 2,900
Tax Adjustments, Settlements, and Unusual Provisions	$ 2,500