Revenue Recognition (Reagent Rental Programs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Lease receivable asset	$ 1.3
Instruments transferred to property and equipment	2.0
Operating-type reagent rental programs
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Instruments transferred to property and equipment		$ 4.0
Reagent rental programs
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Estimation of future revenues	$ 38.1