3. Fair Value Measurements 3. Contingent Consideration (Details) - USD ($) $ in Millions		3 Months Ended		28 Months Ended
		Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Oct. 01, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value		$ 3.5	$ 4.9
Business Combination, Contingent Consideration, Liability					$ 0.6
Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration milestone payments		(1.3)
Business Combination, Contingent Consideration, Liability		2.9
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances		(0.1)		$ (13.9)
Distributor [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration milestone payments		(1.4)	(0.7)
Business Combination, Contingent Consideration, Liability		0.6
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances		$ 0.0
Sales milestone percentage of annual invoices [Member] | Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Acquisition, Contingent Consideration, Potential Percentage Payout		39.00%
Sales milestone percentage of annual invoices low [Member] | Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Acquisition, Contingent Consideration, Potential Percentage Payout		20.00%
Sales milestone minimum amount [Member] | Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low		$ 0.0
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	[1]	3.5	4.9
Other Noncurrent Liabilities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	[1]	0.0	1.6
Other Current Liabilities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	[1]	$ 3.5	$ 3.3

[1] Contingent consideration liability is included in the following accounts in the Condensed Consolidated Balance Sheets (in millions):
  March 31, 2020   December 31, 2019 Other current liabilities $ 3.5
  $ 3.3
Other long-term liabilities —
  1.6
   Total $ 3.5
  $ 4.9