CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Jun. 28, 2019	Jun. 29, 2018
Statement of Cash Flows [Abstract]
Net earnings	$ 221.8	$ 33.5
Adjustments to reconcile net earnings to net cash provided by operating activities:
Share-based compensation expense	35.2	34.0
Depreciation	38.7	38.3
Amortization of intangible assets	17.4	15.2
Deferred taxes	8.9	50.1
Provision for doubtful accounts receivable	6.2	2.7
Gain on sale of equity investments, net	(21.8)	0.0
Impairment charges	50.6	22.1
Write-off of in-process research and development related to acquisition-related activities	20.8	0.0
Loss on hedges related to acquisition-related activities	0.0	5.5
Other, net	(1.2)	1.3
Changes in assets and liabilities, net of effects of acquisitions:
Trade and unbilled receivables	(77.7)	10.8
Inventories	(78.4)	(48.5)
Prepaid expenses and other assets	(26.9)	(29.8)
Accounts payable	29.9	27.8
Accrued liabilities and other long-term liabilities	(24.4)	150.0
Deferred revenues	54.9	33.7
Net cash provided by operating activities	254.0	346.7
Cash flows from investing activities:
Purchases of property, plant and equipment	(43.7)	(30.8)
Acquisitions, net of cash acquired	(485.6)	(58.7)
Purchase of equity investments	(29.8)	(10.1)
Sale of equity investment	29.9	0.0
Principal payments on notes receivable	0.1	6.3
Investment in available-for-sale security	0.0	(6.0)
Sale of available-for-sale security	8.5	8.0
Loans to CPTC	(1.4)	(5.3)
Purchase of foreign currency option related to acquisition-related activities	0.0	(5.5)
Other, net	(1.7)	(1.0)
Net cash used in investing activities	(523.7)	(103.1)
Cash flows from financing activities:
Repurchases of common stock	(134.2)	(131.9)
Proceeds from issuance of common stock to employees	55.7	57.1
Tax withholdings on vesting of equity awards	(14.1)	(11.5)
Cash received from Varex Imaging Corporation	4.1	0.0
Borrowings under credit facility agreement	430.0	503.3
Repayments under credit facility agreement	(430.0)	(503.3)
Net proceeds (repayments) under the credit facility agreements with maturities less than 90 days	400.0	(331.7)
Repayment of acquired debt	(16.8)	0.0
Other	(0.7)	(3.6)
Net cash provided by (used in) financing activities	294.0	(421.6)
Effects of exchange rate changes on cash, cash equivalents, and restricted cash	2.2	4.6
Net increase (decrease) in cash, cash equivalents, and restricted cash	26.5	(173.4)
Cash, cash equivalents, and restricted cash at beginning of period	516.4	718.5
Cash, cash equivalents, and restricted cash at end of period	$ 542.9	$ 545.1