Income Taxes - Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets arising from:
Loss carryforwards	$ 104,890	$ 109,299
Intangible assets, net	0	1,825
Pension and other benefit accruals	18,180	12,457
Tax credits	1,567	1,582
Investments	2,821	2,102
Interest and finance fees	1,697	2,975
Other allowances and accruals, net	13,334	14,855
Total	142,489	145,095
Deferred tax liabilities arising from:
Property and equipment, net	23,897	29,174
Intangible assets, net	4,188	2,731
Foreign income inclusions	7,178	16,455
Other allowances and accruals, net	165	143
Valuation allowance	102,795	99,860
Net deferred tax liability	35,428	48,503
Net deferred tax (asset) liability	$ (4,266)	$ 3,268