Acquisitions Acquisition (Mortara Instruments) (Details) - USD ($) $ in Millions		9 Months Ended
	Feb. 14, 2017	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2016
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired		$ 311.4	$ 0.0
Goodwill		$ 1,751.6		$ 1,584.4
Mortara [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 330.0
Payments to Acquire Businesses, Net of Cash Acquired	311.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	16.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	21.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	2.8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	18.1
Goodwill	165.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	3.8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	(22.6)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	(1.3)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	311.2
Trade names (7-year weighted average useful life) | Mortara [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	15.8
Trade names (7-year weighted average useful life) | Mortara [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		7 years
Customer relationships (8-year useful life) | Mortara [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		8 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	37.8
Developed technology (7-year useful life) | Mortara [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		7 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 53.6
Senior Unsecured 5.00% Notes due on February 14, 2025 [Member]
Business Acquisition [Line Items]
Aggregate value of debt		$ 300.0