Income Taxes - Significant Components of Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Carry-forward losses and credits	$ 54.2	$ 59.2
Inventory and warranty reserves	32.4	29.7
Accrued expenses and other reserves	14.5	12.6
Stock-based compensation	5.1	8.6
Executive supplemental retirement benefits	1.8	1.6
Lease liability	48.7	15.3
Deferred tax assets utilization loss	4.0	2.7
Other	2.7	2.3
Total deferred tax assets	163.4	132.0
Deferred tax liabilities:
Acquired intangible assets and goodwill	(116.2)	(128.1)
Depreciation and amortization	(14.5)	(14.1)
Loan costs	(1.8)	(2.3)
Right-of-use asset	(46.4)	(14.4)
Foreign withholding taxes	(3.2)	(5.0)
Total deferred tax liabilities	(182.1)	(163.9)
Valuation allowance	(30.6)	(27.4)
Net deferred tax (liabilities) assets	$ (49.3)	$ (59.3)