3. Fair Value Measurements 3. Contingent Consideration (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended	28 Months Ended
		Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value		$ 5.3		$ 5.3		$ 8.4
Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration milestone payments		(1.1)	$ (1.4)	(2.5)
Business Combination, Contingent Consideration, Liability		$ 5.3		5.3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances				$ (0.6)	$ (12.9)
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%		39.00%
Market Price of Risk [Member] | Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate				11.40%
Projected Volatility of Growth Rate [Member] | Analytical Flow Cytometer Platform [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate				3.90%
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%		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		$ 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]	5.3		5.3		8.4
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]	1.6		1.6		5.2
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]	$ 3.7		$ 3.7		$ 3.2

[1] Contingent consideration liability is included in the following accounts in the Condensed Consolidated Balance Sheets (in millions):
  September 30, 2019   December 31, 2018 Other current liabilities $ 3.7
  $ 3.2
Other long-term liabilities 1.6
  5.2
   Total $ 5.3
  $ 8.4