Schedule of Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Debt Instrument [Line Items]
Principal amount	$ 1,486,496
Total debt	1,366,464	$ 1,342,428
Less current portion	28,478	9,428
Total long-term debt	1,337,986	1,333,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	$ 160,000	$ 0
Convertible Debt 2021 Notes [Member]
Debt Instrument [Line Items]
Interest rate	1.875%	1.875%	1.875%
Principal amount	$ 575,000	$ 575,000
Unamortized discount	(117,119)	(124,735)
Total debt	457,881	450,265
Term Loans [Member]
Debt Instrument [Line Items]
Total debt	747,087	890,479
Other borrowings [Member]
Debt Instrument [Line Items]
Total debt	$ 1,496	$ 1,684