Goodwill and Acquired Intangible Assets, Net (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Acquired Intangible Assets Net [Abstract]

Schedule of Finite-Lived Intangible Assets [Table Text Block]

The following table summarizes intangible assets as of December 31, 2018 and 2017:

	As of December 31, 2018					As of December 31, 2017
(in thousands)	Gross Carrying Amount		Accumulated Amortization			Gross Carrying Amount		Accumulated Amortization
Customer relationships	$	199,581	$	(133,863	)	$	207,133	$	(124,967	)
Trademarks and trade names	45,233		(25,837		)	56,273		(25,768		)
Software	58,515		(29,420		)	62,384		(25,142		)
Non-compete agreements	2,076		(1,800		)	3,895		(3,265		)
Total	$	305,405	$	(190,920	)	$	329,685	$	(179,142	)

Schedule of Intangible Assets and Goodwill [Table Text Block]

The following table summarizes the goodwill and amortizable intangible assets activity for the years ended December 31, 2018 and 2017:

(in thousands)	Acquired Intangible Assets			Goodwill			Total Intangible Assets
Balance as of January 1, 2017	$	165,331		$	689,713		$	855,044
Increases (decreases):
Impairment	(2,286		)	(31,770		)	(34,056		)
Amortization	(24,527		)	—			(24,527		)
Other (primarily changes in foreign currency exchange rates)	12,025			59,443			71,468
Balance as of December 31, 2017	150,543			717,386			867,929
Increases (decreases):
Acquisitions	—			20,742			20,742
Impairment	(7,049		)	—			(7,049		)
Amortization	(22,562		)	—			(22,562		)
Other (primarily changes in foreign currency exchange rates)	(6,447		)	(33,931		)	(40,378		)
Balance as of December 31, 2018	$	114,485		$	704,197		$	818,682