Goodwill and Acquired Intangible Assets, Net (Tables)

6 Months Ended

Jun. 30, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets and Goodwill [Table Text Block]

A summary of acquired intangible assets and goodwill activity for the six months ended June 30, 2016 is presented below:

(in thousands)	Acquired Intangible Assets			Goodwill			Total Intangible Assets
Balance as of December 31, 2015	$	167,972		$	685,178		$	853,150
Increases (Decreases):
Acquisitions	5,022			(2,558		)	2,464
Amortization	(12,781		)	—			(12,781		)
Other (primarily changes in foreign currency exchange rates)	(603		)	6,269			5,666
Balance as of June 30, 2016	$	159,610		$	688,889		$	848,499