General and Basis of Presentation - Restructuring Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 2,008	$ 3,583	$ 6,557	$ 7,046
Operating Segments | Europe & Africa
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	1,894	2,335	4,971	2,735
Operating Segments | North America
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	0	799	1,205	1,012
Operating Segments | Australia & New Zealand
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	114	0	114	0
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 0	$ 449	$ 267	$ 3,299