Goodwill and Acquired Intangible Assets, Net (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Goodwill and Finite-lived Intangible Assets Rollforward [Roll Forward]
Finite-Lived Intangible Assets, Net	$ 159,610	$ 167,972
Finite-Lived Intangible Assets, Amortization Expense	(12,781)
Finite-lived intangible assets, other changes	(603)
Goodwill	688,889	685,178
Goodwill, Other Changes	6,269
Intangible Assets, Net (Including Goodwill)	848,499	$ 853,150
Total intangible assets amortization expense	(12,781)
Total intangible assets, other changes	5,666
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	12,400
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	22,900
Finite-Lived Intangible Assets, Amortization Expense, Year Two	20,600
Finite-Lived Intangible Assets, Amortization Expense, Year Three	19,900
Finite-Lived Intangible Assets, Amortization Expense, Year Four	19,300
Finite-Lived Intangible Assets, Amortization Expense, Year Five	18,300
Finite-lived Intangible Assets Acquired	5,022
Goodwill, Acquired During Period	(2,558)
Total intangible assets acquired during period	$ 2,464