Nature of Business (Details) - Disposal Group, Disposed of by Sale, Not Discontinued Operations - Infectious Disease Business - USD ($) $ in Millions	Jan. 05, 2018	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total sale price	$ 166.4
Consideration received (in shares)	3,313,702
Consideration received, market value	$ 54.5
Receivable due in 12 months	25.0	$ 24.1
Receivable due in 18 months	$ 25.0	$ 24.2
Minimum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Tiered royalty payments, percent of net sales	5.00%
Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Tiered royalty payments, percent of net sales	25.00%