Leases - Schedule of Information Reported in Condensed Consolidated Statement of Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 6.2	$ 5.1
Operating cash flows from finance leases	0.3	0.4
Financing cash flows from finance leases	3.4	3.0
Assets obtained in exchange for lease obligations:
Adoption of accounting principal ASC 842		82.3
Operating leases	0.4	2.6
Finance leases	$ 0.1	0.1
ASU 2016-02 [Member]
Assets obtained in exchange for lease obligations:
Adoption of accounting principal ASC 842		$ 82.3