Goodwill and Intangible Assets Goodwill, Changes in Carrying values (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Document Period End Date	Dec. 31, 2018
Balance as of September 30, 2018	$ 3,247,105
Acquisitions		$ 6,800
Purchase accounting adjustments	17
Effect of foreign currency translation	(8,784)
Balance as of December 31, 2018	3,238,338
Healthcare
Goodwill [Line Items]
Balance as of September 30, 2018	1,430,325
Purchase accounting adjustments	17
Effect of foreign currency translation	(2,297)
Balance as of December 31, 2018	1,428,045
Enterprise
Goodwill [Line Items]
Balance as of September 30, 2018	683,347
Purchase accounting adjustments	0
Effect of foreign currency translation	(2,387)
Balance as of December 31, 2018	680,960
Automotive
Goodwill [Line Items]
Balance as of September 30, 2018	1,119,947
Purchase accounting adjustments	0
Effect of foreign currency translation	(3,693)
Balance as of December 31, 2018	1,116,254
Other
Goodwill [Line Items]
Balance as of September 30, 2018	13,486
Purchase accounting adjustments	0
Effect of foreign currency translation	(407)
Balance as of December 31, 2018	$ 13,079