Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 152,158
Foreign exchange impact			33
Goodwill, ending balance	$ 152,191		152,191		$ 152,158
Goodwill impairment	0	$ 27,887	0	$ 27,887
North America
Goodwill [Roll Forward]
Goodwill, beginning balance			152,158
Foreign exchange impact			33
Goodwill, ending balance	$ 152,191		$ 152,191		152,158
Reporting unit, threshold maximum percentage of fair value in excess of carrying amount	30.00%		30.00%
Goodwill impairment					18,400	$ 75,400
EMEA
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 0
Foreign exchange impact			0
Goodwill, ending balance	$ 0		0		0
Goodwill impairment		20,800
LATAM
Goodwill [Roll Forward]
Goodwill, beginning balance			0
Foreign exchange impact			0
Goodwill, ending balance	$ 0		$ 0		$ 0
Goodwill impairment		$ 7,100