Net Sales - Summary of Net Sales by Product Line and Geography (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Net sales	$ 1,686.9	$ 1,754.9	$ 1,875.4	$ 1,872.1	$ 1,318.0
Residential Roofing Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	846.4				695.0
Non-Residential Roofing Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	487.7				329.7
Complementary Building Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	352.8				293.3
U.S. [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1,644.1				1,283.6
U.S. [Member] | Residential Roofing Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	835.8				686.1
U.S. [Member] | Non-Residential Roofing Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	457.4				305.9
U.S. [Member] | Complementary Building Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	350.9				291.6
Canada [Member]
Disaggregation Of Revenue [Line Items]
Net sales	42.8				34.4
Canada [Member] | Residential Roofing Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	10.6				8.9
Canada [Member] | Non-Residential Roofing Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	30.3				23.8
Canada [Member] | Complementary Building Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 1.9				$ 1.7