Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accrued Liabilities, Current [Abstract]
Interest	$ 28,513	$ 28,685
Employee related costs	77,020	102,608
Income taxes payable	10,143	11,876
Other accrued expenses	38,423	61,617
Total accrued liabilities	$ 154,099	$ 204,786