Goodwill and Acquired Intangible Assets, Net (Tables)

3 Months Ended

Mar. 31, 2014

Goodwill and Acquired Intangible Assets Net [Abstract]

Schedule of Intangible Assets and Goodwill [Table Text Block]

A summary of acquired intangible assets and goodwill activity for the three months ended March 31, 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):
Amortization	(4,841		)	—		(4,841		)
Other (primarily changes in foreign currency exchange rates)	758			1,245		2,003
Balance as of March 31, 2014	$	88,943		$	499,680	$	588,623