Business Segment, Geographic Area, Product/Service Offerings and Significant Customer Information - Reconciliation of Segment Assets to Consolidated Total Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	$ 858.1	$ 803.2
Cash and cash equivalents	493.3	414.6
Short-term investments	222.4	109.4
Other current assets	95.9	106.3
Property, plant and equipment, net	267.9	241.9
Right-of-use asset	180.1	64.5
Other assets and long-term investments	41.5	47.5
Consolidated total assets	3,750.9	3,416.3
Segment Reconciling Items [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	493.3	414.6
Short-term investments	222.4	109.4
Other current assets	95.9	106.3
Property, plant and equipment, net	267.9	241.9
Right-of-use asset	180.1	64.5
Goodwill and intangible assets, net	1,585.4	1,623.1
Other assets and long-term investments	47.8	53.3
Consolidated total assets	$ 3,750.9	$ 3,416.3