Revenue - Disaggregation of Sales - Schedule of Disaggregates of Net Sales of our Component Products and Real Estate Management and Development Segments (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Disaggregation Of Revenue [Line Items]
Net sales	$ 509.0	$ 459.3
Component Products
Disaggregation Of Revenue [Line Items]
Net sales	35.9	32.3
Component Products \| Security Products
Disaggregation Of Revenue [Line Items]
Net sales	25.9	25.5
Component Products \| Marine Components
Disaggregation Of Revenue [Line Items]
Net sales	10.0	6.8
Real Estate Management And Development
Disaggregation Of Revenue [Line Items]
Net sales	8.1	6.0
Real Estate Management And Development \| Land Sales
Disaggregation Of Revenue [Line Items]
Net sales	6.6	3.6
Real Estate Management And Development \| Water Delivery
Disaggregation Of Revenue [Line Items]
Net sales	1.0	1.9
Real Estate Management And Development \| Utility and Other
Disaggregation Of Revenue [Line Items]
Net sales	$ 0.5	$ 0.5

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details