Revenue - Business Revenue (Details) - USD ($)	3 Months Ended
	Dec. 26, 2020	Dec. 28, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 1,609,800,000	$ 850,500,000
Contract with Customer, Liability, Revenue Recognized	50,700,000
United States
Disaggregation of Revenue [Line Items]
Revenues	1,137,800,000	632,700,000
International
Disaggregation of Revenue [Line Items]
Revenues	472,000,000.0	217,800,000
Diagnostics
Disaggregation of Revenue [Line Items]
Revenues	1,128,200,000	311,500,000
Diagnostics | United States
Disaggregation of Revenue [Line Items]
Revenues	763,500,000	231,600,000
Diagnostics | International
Disaggregation of Revenue [Line Items]
Revenues	364,700,000	79,900,000
Diagnostics | Cytology & Perinatal
Disaggregation of Revenue [Line Items]
Revenues	124,800,000	121,000,000.0
Diagnostics | Cytology & Perinatal | United States
Disaggregation of Revenue [Line Items]
Revenues	80,100,000	77,500,000
Diagnostics | Cytology & Perinatal | International
Disaggregation of Revenue [Line Items]
Revenues	44,700,000	43,500,000
Diagnostics | Molecular Diagnostics
Disaggregation of Revenue [Line Items]
Revenues	995,300,000	178,500,000
Diagnostics | Molecular Diagnostics | United States
Disaggregation of Revenue [Line Items]
Revenues	675,300,000	142,100,000
Diagnostics | Molecular Diagnostics | International
Disaggregation of Revenue [Line Items]
Revenues	320,000,000.0	36,400,000
Diagnostics | Blood Screening
Disaggregation of Revenue [Line Items]
Revenues	8,100,000	12,000,000.0
Diagnostics | Blood Screening | United States
Disaggregation of Revenue [Line Items]
Revenues	8,100,000	12,000,000.0
Diagnostics | Blood Screening | International
Disaggregation of Revenue [Line Items]
Revenues	0	0
Breast Health
Disaggregation of Revenue [Line Items]
Revenues	332,700,000	331,100,000
Breast Health | United States
Disaggregation of Revenue [Line Items]
Revenues	258,200,000	256,500,000
Breast Health | International
Disaggregation of Revenue [Line Items]
Revenues	74,500,000	74,600,000
Breast Health | Breast Imaging
Disaggregation of Revenue [Line Items]
Revenues	267,700,000	274,800,000
Breast Health | Breast Imaging | United States
Disaggregation of Revenue [Line Items]
Revenues	203,000,000.0	209,400,000
Breast Health | Breast Imaging | International
Disaggregation of Revenue [Line Items]
Revenues	64,700,000	65,400,000
Breast Health | Interventional Breast Solutions
Disaggregation of Revenue [Line Items]
Revenues	65,000,000.0	56,300,000
Breast Health | Interventional Breast Solutions | United States
Disaggregation of Revenue [Line Items]
Revenues	55,200,000	47,100,000
Breast Health | Interventional Breast Solutions | International
Disaggregation of Revenue [Line Items]
Revenues	9,800,000	9,200,000
GYN Surgical
Disaggregation of Revenue [Line Items]
Revenues	124,000,000.0	119,100,000
GYN Surgical | United States
Disaggregation of Revenue [Line Items]
Revenues	101,000,000.0	98,800,000
GYN Surgical | International
Disaggregation of Revenue [Line Items]
Revenues	23,000,000.0	20,300,000
Medical Aesthetics
Disaggregation of Revenue [Line Items]
Revenues	0	65,300,000
Medical Aesthetics | United States
Disaggregation of Revenue [Line Items]
Revenues		30,900,000
Medical Aesthetics | International
Disaggregation of Revenue [Line Items]
Revenues		34,400,000
Skeletal Health
Disaggregation of Revenue [Line Items]
Revenues	24,900,000	23,500,000
Skeletal Health | United States
Disaggregation of Revenue [Line Items]
Revenues	15,100,000	14,900,000
Skeletal Health | International
Disaggregation of Revenue [Line Items]
Revenues	$ 9,800,000	$ 8,600,000