Consolidated Statements of Comprehensive Loss - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Mar. 30, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (272.6)	$ (681.4)	$ (174.0)	$ (274.7)
Changes in foreign currency translation adjustment	2.4	10.1	(0.8)	15.6
Loss reclassified from accumulated other comprehensive loss to the statements of operations	0.0	0.0	0.0	0.4
Changes in pension plans, net of taxes of $0.6 for the six months ended March 31, 2018:	0.0		0.0	0.6
Changes in value of hedged interest rate caps, net of tax of $0.3 and $0.8 for the three and six months ended March 30, 2019 and $0.3 and $(4.6) for the three and six months ended March 31, 2018:	(1.5)	0.7	(5.4)	(3.6)
Loss reclassified from accumulated other comprehensive loss to the statements of operations	0.5	0.3	1.2	2.6
Other comprehensive income (loss)	1.4	11.1	(5.0)	15.6
Comprehensive loss	$ (271.2)	$ (670.3)	$ (179.0)	$ (259.1)