Intangible Assets and Goodwill Future Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense associated with intangible assets	$ 57,600	$ 32,900	$ 29,400
2018	57,963
2019	53,132
2020	52,913
2021	52,823
2022	52,823
Thereafter	1,297,264
Total	$ 1,566,918	$ 1,436,379