Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount		$ 6,200
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	35.00%
Current
Federal		$ (651)	$ 0	$ (1,310)
State		799	783	2,022
Foreign		4,100	3,328	7,371
Total current		4,248	4,111	8,083
Deferred
Federal		686	0	191
State		(648)	(610)	(1,613)
Foreign		(3,086)	(1,198)	1,043
Total deferred		(3,048)	(1,808)	(379)
Provision (benefit) for income taxes		1,200	2,303	7,704
Effective Income Tax Rate Reconciliation Detail [Table]
Income tax provision (benefit) computed at statutory federal income tax rates		(21,344)	(82,982)	(70,617)
State income taxes (net of federal benefit)		1,664	(2,960)	(608)
Nondeductible expenses		472	419	909
Impact of international operations		10,860	7,567	(1,880)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount		54,092	0	0
Goodwill impairments		0	12,990	20,412
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Amount		5,151	2,247	1,411
Valuation allowance		(55,850)	58,846	55,392
Other		6,155	6,176	2,685
Provision (benefit) for income taxes		1,200	2,303	7,704
Domestic and Foreign Income Before Tax Detail [Table]
Domestic		(46,356)	(235,394)	(195,815)
International		(14,627)	(1,696)	(5,948)
Total		(60,983)	(237,090)	(201,763)
Unrecognized Tax Benefit Liability Rollforward Detail [Table]
Gross unrecognized tax benefits at beginning of period		1,593	1,955	1,959
Decreases in tax positions for prior years		0	0	0
Increases in tax positions for current year		0	16	120
Lapse in statute of limitations		(327)	(378)	(124)
Gross unrecognized tax benefits at end of period	$ 1,266	1,266	1,593	1,955
Recognized interest and penalties		(200)	(100)	300
Accrued potential interest and penalties	2,000	2,000	2,300
Amount of unrecognized tax benefits that would affect effective tax rate	3,100	3,100	3,200
Deferred tax assets:
Net operating losses	88,025	88,025	126,141
Foreign tax credits and alternative minimum tax credits	19,346	19,346	28,929
Accruals	24,577	24,577	31,835
Deferred Tax Assets, Tax Credit Carryforwards, Amortization for book in excess of tax expense	40,979	40,979	67,183
All other	3,813	3,813	8,932
Total deferred tax assets	176,740	176,740	263,020
Valuation allowance	(130,453)	(130,453)	(185,275)
Net deferred tax assets	46,287	46,287	77,745
Deferred tax liabilities:
Excess book over tax basis in property, plant, and equipment	48,618	48,618	83,311
All other	2,064	2,064	1,702
Total deferred tax liability	50,682	50,682	85,013
Net deferred tax liability	4,395	4,395	7,268
Increase (decrease) in valuation allowance		(54,800)	58,600	$ 53,000
Foreign and state net operating loss carryforwards	62,300	62,300
Operating Loss Carryforwards	12,800	12,800
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	12,900	12,900
Foreign tax credits	19,100	$ 19,100
Tax Adjustments, Settlements, and Unusual Provisions	$ 4,500		$ 49,600