Stockholders' Equity - Secondary Offerings (Details) - $ / shares	Feb. 28, 2019	Sep. 14, 2018	May 29, 2018	Nov. 20, 2017	Jul. 25, 2017	Dec. 26, 2019	May 02, 2017
Stockholders' Equity
Number of shares sold by stockholders	10,000,000	11,500,000	10,000,000	7,475,000	10,718,550
Share price	$ 37.50	$ 37.25	$ 45.80	$ 36.00	$ 40.00	$ 50.30	$ 21.00

The number of shares of stock sold by stockholders in a secondary offering.

No definition available.

Name:	fnd_SaleOfStockByShareholdersNumberOfSharesSold
Namespace Prefix:	fnd_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration