CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Millions	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Statement of Comprehensive Income [Abstract]
Net earnings	$ 250.3	$ 402.7	$ 412.0
Defined benefit pension and post-retirement benefit plans:
Net gain (loss) arising during the year, net of tax (expense) benefit of ($2.5), $4.3 and $0.9	10.0	(21.4)	(4.7)
Prior service credit arising during the year, net of tax expense of ($0.7), ($0.2) and $0.0	4.3	1.1	0.0
Amortization of prior service cost included in net periodic benefit cost, net of tax benefit of $0.2, $0.2 and $0.1	(0.8)	(0.4)	(0.2)
Amortization, settlement and curtailment of net actuarial loss included in net periodic benefit cost, net of tax expense of ($1.0), ($0.5) and ($0.6)	5.7	3.5	2.9
Defined benefit pension and post-retirement benefit plans	19.2	(17.2)	(2.0)
Derivative instruments:
Change in unrealized gain (loss), net of tax (expense) benefit of $0.0, $0.4 and ($0.8)	0.0	(0.6)	1.4
Reclassification adjustments, net of tax (expense) benefit of $0.0, ($0.4) and $1.4	0.0	0.6	(2.4)
Derivative instruments	0.0	0.0	(1.0)
Available-for-sale securities:
Change in unrealized loss, net of tax benefit of $0.0, $0.1 and $0.1	0.0	(0.3)	(0.1)
Reclassification adjustments, net of tax expense of $0.0, ($0.2) and $0.0	0.0	0.4	0.0
Available-for-sale securities	0.0	0.1	(0.1)
Currency translation adjustment	12.8	2.8	(24.8)
Other comprehensive earnings (loss)	32.0	(14.3)	(27.9)
Comprehensive earnings	282.3	388.4	384.1
Less: Comprehensive earnings attributable to noncontrolling interests	0.7	0.4	0.5
Comprehensive earnings attributable to Varian	$ 281.6	$ 388.0	$ 383.6