Segment Information - Schedule of Goodwill and Intangible Assets Net of Accumulated Amortization (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Goodwill	$ 161.4	$ 177.0
Intangible assets, net of accumulated amortization	91.8	93.5
U.S. Operations [Member]
Segment Reporting Information [Line Items]
Goodwill	123.5	123.5
Intangible assets, net of accumulated amortization	0.0	0.5
International Operations [Member]
Segment Reporting Information [Line Items]
Goodwill	37.9	53.5
Intangible assets, net of accumulated amortization	$ 91.8	$ 93.0