Operating Results Information for each Business Segment (Detail) (USD $)	3 Months Ended								12 Months Ended
	Sep. 28, 2012	Jul. 01, 2012	Apr. 01, 2012	Dec. 31, 2011	Sep. 30, 2011	Jul. 01, 2011	Apr. 01, 2011	Dec. 31, 2010	Sep. 28, 2012	Sep. 30, 2011	Oct. 01, 2010
Segment Reporting Information [Line Items]
Revenues	$ 756,100,000	$ 705,300,000	$ 720,300,000	$ 625,300,000	$ 719,000,000	$ 649,400,000	$ 648,400,000	$ 579,900,000	$ 2,807,015,000	$ 2,596,666,000	$ 2,356,585,000
Operating Earnings (Loss)									594,074,000	588,451,000	534,202,000
Depreciation & Amortization									61,000,000	53,000,000	48,000,000
Capital Additions									67,000,000	71,000,000	52,000,000
Total Assets	2,878,726,000				2,498,761,000				2,878,726,000	2,498,761,000	2,324,000,000
Goodwill	222,242,000				212,452,000				222,242,000	212,452,000	208,500,000
Oncology Systems
Segment Reporting Information [Line Items]
Revenues									2,189,000,000	2,022,000,000	1,862,000,000
Operating Earnings (Loss)									505,000,000	507,000,000	462,000,000
Depreciation & Amortization									23,000,000	19,000,000	19,000,000
Capital Additions									17,000,000	17,000,000	14,000,000
Total Assets	1,220,000,000				1,093,000,000				1,220,000,000	1,093,000,000	1,000,000,000
Goodwill	132,000,000				130,500,000				132,000,000	130,500,000	126,700,000
X-Ray Products
Segment Reporting Information [Line Items]
Revenues									493,000,000	469,000,000	403,000,000
Operating Earnings (Loss)									131,000,000	118,000,000	100,000,000
Depreciation & Amortization									10,000,000	8,000,000	7,000,000
Capital Additions									8,000,000	7,000,000	6,000,000
Total Assets	265,000,000				268,000,000				265,000,000	268,000,000	186,000,000
Goodwill	17,000,000				6,100,000				17,000,000	6,100,000	4,500,000
Total Reportable Segments
Segment Reporting Information [Line Items]
Revenues									2,682,000,000	2,491,000,000	2,265,000,000
Operating Earnings (Loss)									636,000,000	625,000,000	562,000,000
Depreciation & Amortization									33,000,000	27,000,000	26,000,000
Capital Additions									25,000,000	24,000,000	20,000,000
Total Assets	1,485,000,000				1,361,000,000				1,485,000,000	1,361,000,000	1,186,000,000
Goodwill	149,000,000				136,000,000				149,000,000	136,000,000	131,000,000
Other
Segment Reporting Information [Line Items]
Revenues									125,000,000	106,000,000	92,000,000
Operating Earnings (Loss)									(32,000,000)	(32,000,000)	(30,000,000)
Depreciation & Amortization									4,000,000	3,000,000	3,000,000
Capital Additions									10,000,000	13,000,000	7,000,000
Total Assets	313,000,000				239,000,000				313,000,000	239,000,000	215,000,000
Goodwill	73,200,000				75,900,000				73,200,000	75,900,000	77,300,000
Corporate
Segment Reporting Information [Line Items]
Revenues									0	0	0
Operating Earnings (Loss)									(10,000,000)	(5,000,000)	2,000,000
Depreciation & Amortization									24,000,000	23,000,000	19,000,000
Capital Additions									32,000,000	34,000,000	25,000,000
Total Assets	1,081,000,000				899,000,000				1,081,000,000	899,000,000	923,000,000
Goodwill	$ 0				$ 0				$ 0	$ 0	$ 0