Goodwill and Other Intangible Assets (Schedule Of Intangible Assets Gross Carrying Amounts And Accumulated Amortization) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 14, 2018	Sep. 30, 2017	Aug. 30, 2017	May 25, 2017	May 08, 2017	Nov. 07, 2016	Sep. 30, 2016	Jan. 29, 2016
Goodwill and Other Intangible Assets [Line Items]
Goodwill	$ 381,652	$ 3,500	$ 377,879	$ 10,700	$ 4,800	$ 7,500	$ 30,100	$ 323,600	$ 10,200
Patents [Member]
Goodwill and Other Intangible Assets [Line Items]
Gross carrying amount	1,800		1,000
Less: accumulated amortization	800		800
Net	1,000		200
Capitalized Software [Member]
Goodwill and Other Intangible Assets [Line Items]
Gross carrying amount	71,300		63,000
Less: accumulated amortization	41,600		34,400
Net	29,700		28,600
Customer relationships [Member]
Goodwill and Other Intangible Assets [Line Items]
Gross carrying amount	185,300		181,900
Less: accumulated amortization	47,800		37,400
Net	137,500		144,500
Other [Member]
Goodwill and Other Intangible Assets [Line Items]
Gross carrying amount	5,500		5,400
Less: accumulated amortization	2,000		1,400
Net	3,500		4,000
Trade names [Member]
Goodwill and Other Intangible Assets [Line Items]
Trade names	$ 173,700		$ 173,800