Acquisitions and Dispositions (Revenues and Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017
BWI
Business Acquisition [Line Items]
Net Sales	$ 13,168
Net income (loss) attributable to Masonite	(1,231)
Graham & Maiman
Business Acquisition [Line Items]
Net Sales	38,901
Net income (loss) attributable to Masonite	314
DW3
Business Acquisition [Line Items]
Net Sales	68,474
Net income (loss) attributable to Masonite	6,712
2018 Acquisitions
Business Acquisition [Line Items]
Net Sales	120,543
Net income (loss) attributable to Masonite	$ 5,795
A&F Wood Products, Inc.
Business Acquisition [Line Items]
Net Sales		$ 3,883
Net income (loss) attributable to Masonite		$ 825