Operating Segments and Geographic Information (Schedule Of Segment Income Statement Footnote) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) stores	Dec. 31, 2015 USD ($) stores	Dec. 31, 2014 USD ($) stores
Segment Reporting Information [Line Items]
Asset impairments	$ 1,449	$ 930	$ 572	$ 193	$ 7,771	$ 5,460	$ 2,075	$ 0	$ 3,144	$ 15,306	$ 8,827
Goodwill impairment									431
Operating Segments [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Asset impairments									$ 1,700	$ 7,200	$ 4,000
Underperforming retail locations | stores									12	27	36
Operating Segments [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Asset impairments									$ 700	$ 700	$ 2,800
Underperforming retail locations | stores									21	27	14
Operating Segments [Member] | South Africa [Member]
Segment Reporting Information [Line Items]
Asset impairments										$ 5,700
Underperforming retail locations | stores										9
Operating Segments [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Asset impairments									$ 300	$ 1,600	$ 2,000
Underperforming retail locations | stores									9	21	27
Goodwill impairment									$ 400