Financial Commitments (Long-Term Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total debt	$ 800,521	$ 817,684
Less - current maturities	(120,256)	(88,917)
Long-term debt, net	680,265	728,767
Term Loan [Member]
Debt Instrument [Line Items]
Total debt	83,911	222,120
Senior Notes [Member]
Debt Instrument [Line Items]
Total debt	297,616	297,118
Convertible Notes [Member]
Debt Instrument [Line Items]
Total debt	148,606
Equipment Financing, Mortgages And Acquisition-Related Notes [Member]
Debt Instrument [Line Items]
Total debt	116,179	133,288
Other Indebtedness [Member]
Debt Instrument [Line Items]
Total debt	6,139	9,343
Revolver [Member]
Debt Instrument [Line Items]
Total debt	$ 148,070	$ 155,815