Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities [Abstract]
Interest Payable, Current	$ 28,246	$ 28,685
Employee-related Liabilities, Current	119,931	102,608
Accrued Income Taxes, Current	2,112	11,876
Other Accrued Liabilities, Current	50,504	61,617
Accrued Liabilities, Current	$ 200,793	$ 204,786