Goodwill (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure Text Block Supplement [Abstract]

Schedule of Goodwill [Table Text Block]

	Year ended December 31,
	2018			2019
Balance at the beginning of the year	$	158,559		$	166,094
Acquisitions		11,468			622
Functional currency translation adjustments		(3,933	)		3,987
Balance at year end	$	166,094		$	170,703