Related Party Transactions (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Nanyang Helin Stone Company [Member]
Related Party Transaction [Line Items]
Payments to related party	$ 2,900,000	$ 6,200,000	$ 7,600,000
Related party payables due	0	0
Tile Style [Member]
Related Party Transaction [Line Items]
Payments to related party	1,000,000.0	2,100,000	$ 700,000
Related party payables due	$ 100,000	$ 100,000
Robert Rucker [Member] | Tile Shop Holdings [Member]
Related Party Transaction [Line Items]
Ownership interest	5.00%	5.00%