Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Business Combination, Contingent Consideration, Liability	$ 232,044	$ 347,104
Fair Value, Inputs, Level 1 | Six Point Five Zero Percentage Notes [Domain]
Liabilities:
Long term debt, Carrying Amount	900,000	0
Long term debt, Fair Value	895,500	0
Fair Value, Inputs, Level 1 | 6.75% Notes
Liabilities:
Long term debt, Carrying Amount	0	740,838
Long term debt, Fair Value	$ 0	$ 765,319