Restructuring and Other Charges, net (By Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ (2,820)	$ (6,978)	$ (6,868)	$ (13,000)
Restructuring Charges and Other Expenses	6,329	9,858	13,012	24,499
Healthcare
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(754)	(2,985)	(3,557)	(4,591)
Restructuring Charges and Other Expenses	754	2,985	3,557	4,591
Enterprise
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(446)	(2,700)	(2,255)	(5,264)
Restructuring Charges and Other Expenses	446	2,700	2,255	5,264
Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(54)	116	311	(914)
Restructuring Charges and Other Expenses	54	445	(311)	3,981
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(1,566)	(1,409)	(1,367)	(2,272)
Restructuring Charges and Other Expenses	5,075	3,728	7,511	10,663
Personnel
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(1,422)	(6,352)	(4,335)	(12,565)
Personnel | Healthcare
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(506)	(2,971)	(1,782)	(4,450)
Personnel | Enterprise
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(233)	(2,700)	(1,537)	(5,251)
Personnel | Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	116	0	(914)
Personnel | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(683)	(797)	(1,016)	(1,950)
Facilities
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(1,398)	(626)	(2,533)	(476)
Facilities | Healthcare
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(248)	(14)	(1,775)	(141)
Facilities | Enterprise
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(213)	0	(718)	(13)
Facilities | Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(54)	0	311	0
Facilities | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(883)	(612)	(351)	(322)
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Other Charges	3,509	2,880	6,144	11,458
Other Restructuring [Member] | Healthcare
Restructuring Cost and Reserve [Line Items]
Other Charges	0	0	0	0
Other Restructuring [Member] | Enterprise
Restructuring Cost and Reserve [Line Items]
Other Charges	0	0	0	0
Other Restructuring [Member] | Other
Restructuring Cost and Reserve [Line Items]
Other Charges	0	561	0	3,067
Other Restructuring [Member] | Corporate
Restructuring Cost and Reserve [Line Items]
Other Charges	$ 3,509	$ 2,319	$ 6,144	$ 8,391