Intangible Assets (Schedule Of Indefinite-Lived And Definite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Indefinite-Lived and Finite-Lived Intangible Assets By Major Class [Line Items]
Cost	$ 458,422	$ 348,404
Accumulated amortization	(157,474)	(115,024)
Net book value	300,948	233,380
Trade Names and Trademarks [Member]
Indefinite-Lived and Finite-Lived Intangible Assets By Major Class [Line Items]
Cost	53,871	53,319
Accumulated amortization	(1,595)	(2,028)
Net book value	52,276	51,291
Customer Relationships [Member]
Indefinite-Lived and Finite-Lived Intangible Assets By Major Class [Line Items]
Cost	196,407	124,865
Accumulated amortization	(47,752)	(34,666)
Net book value	148,655	90,199
Computer Software, Intangible Asset [Member]
Indefinite-Lived and Finite-Lived Intangible Assets By Major Class [Line Items]
Cost	206,829	157,776
Accumulated amortization	(108,127)	(78,330)
Net book value	98,702	79,446
Software Under Development [Member]
Indefinite-Lived and Finite-Lived Intangible Assets By Major Class [Line Items]
Cost	1,315	12,444
Net book value	$ 1,315	$ 12,444