Goodwill and Acquired Intangible Assets, Net (Tables)

9 Months Ended

Sep. 30, 2014

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 nine months ended September 30, 2014 is presented below:

(in thousands)	Acquired Intangible Assets			Goodwill			Total Intangible Assets
Balance as of December 31, 2013	$	93,026		$	498,435		$	591,461
Increases (decreases):
Acquisition	102,841			156,748			259,589
Amortization	(17,661		)	—			(17,661		)
Other (primarily changes in foreign currency exchange rates)	(8,022		)	(35,898		)	(43,920		)
Balance as of September 30, 2014	$	170,184		$	619,285		$	789,469