Revenue - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Revenue
Revenue	$ 111,169	$ 111,518
Direct
Revenue
Revenue	66,736	68,195
Tech-enabled
Revenue
Revenue	37,521	35,076
Traditional
Revenue
Revenue	6,912	8,247
Americas
Revenue
Revenue	70,872	69,965
Americas \| Direct
Revenue
Revenue	35,677	35,111
Americas \| Tech-enabled
Revenue
Revenue	28,283	26,607
Americas \| Traditional
Revenue
Revenue	6,912	8,247
Europe
Revenue
Revenue	40,297	41,553
Europe \| Direct
Revenue
Revenue	31,059	33,084
Europe \| Tech-enabled
Revenue
Revenue	$ 9,238	$ 8,469

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration