Intangible Assets, Net and Goodwill - Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense on intangible assets	$ 58,200	$ 63,400	$ 63,900
Future amortization expense, 2018	58,454
Future amortization expense, 2019	58,454
Future amortization expense, 2020	58,454
Future amortization expense, 2021	58,067
Future amortization expense, 2022	$ 57,984