Goodwill and Acquired Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquired intangible assets	$ 6,598	$ 6,752	$ 20,025	$ 20,284
Future amortization expense to be recognized in remainder of 2016	6,600		6,600
Future amortization expense 2017	28,200		28,200
Future amortization expense 2018	24,100		24,100
Future amortization expense 2019	22,100		22,100
Future amortization expense 2020	$ 18,100		$ 18,100