Long-Term Indebtedness (Details 2) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Summary of Long-term debt
Net discount	$ (2,387)	$ (3,281)
Deferred financing costs	(4,787)	(5,386)
Long-term debt and Short-term borrowings	1,651,957	1,505,528
Less current portion	(524)	(7,506)
Total long-term debt	1,651,433	1,498,022
Amended and Restated Term Loan B [Member]
Summary of Long-term debt
Long-term debt	544,750	696,500
Senior Unsecured 2021 Notes [Member]
Summary of Long-term debt
Long-term debt	800,000	800,000
Senior Unsecured 2024 Notes [Member]
Summary of Long-term debt
Long-term debt	300,000	0
HWP Refinance Loan [Member]
Summary of Long-term debt
Long-term debt	29,391	29,667
Amended and Restated Term Loan B and Senior Unsecured 2021 Notes [Member]
Summary of Long-term debt
Deferred financing costs		$ (17,358)
Amended and Restated Term Loan B, Senior Unsecured 2021 and Senior Unsecured 2024 Notes [Member]
Summary of Long-term debt
Deferred financing costs	$ (19,797)