Income Taxes (Details 4) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Components of Deferred Tax Assets [Abstract]
Net operating loss and other credit carryforwards	$ 139,274	$ 44,867
Compensation and benefits	5,480	7,156
Inventories	44	322
Intangible assets	0	16,714
Pension plan	813	1,760
Allowance for doubtful accounts	577	956
Deferred revenue	2,493	4,953
Foreign tax credit and offset to branch deferreds	55,272	56,719
Other	19,127	28,201
less: valuation allowance	(45,614)	(45,682)
Deferred Tax Assets, Net of Valuation Allowance	177,466	115,966
Components of Deferred Tax Liabilities [Abstract]
Intangible assets	(12,849)	(5,074)
Prepaid expenses	0	(1,447)
Property, plant and equipment	(189,529)	(108,646)
Equity Investment in partnerships	(3,572)	(24,315)
Other	(2,010)	(2,402)
Total deferred tax liabilities	(207,960)	(141,884)
Net deferred tax liabilities	$ (30,494)	$ (25,918)