Acquisition - Purchase price allocation (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 18, 2020	Feb. 26, 2022	Feb. 27, 2021
Final purchase price allocation
Business Combination, Bargain Purchase, Gain, Statement of Income or Comprehensive Income [Extensible Enumeration]			Gain (Loss) on Acquisition of Business
Bartell Drug Company
Final purchase price
Cash consideration	$ 89,724
Total purchase price	89,724
Final purchase price allocation
Cash and cash equivalents	3,494
Accounts receivable	23,860
Inventories	67,745
Prepaid expenses and other current assets	1,857
Total current assets	96,956
Property and equipment	28,229
Operating lease right-of-use assets	143,651
Intangible assets	68,700
Other assets	1,805
Total assets acquired	339,341
Accounts payable	24,166
Accrued salaries, wages and other current liabilities	20,335
Current portion of operating lease liabilities	24,617
Total current liabilities	69,118
Long-term operating lease liabilities	124,023
Other long-term liabilities	166
Total liabilities assumed	193,307
Deferred tax liabilities recorded on purchase	13,951
Net assets acquired	132,083
Bargain purchase gain	(42,359)	$ (42,359)	$ (47,705)
Total purchase price	$ 89,724