Income Taxes - Rate reconciliation (Details) - USD ($)			3 Months Ended								12 Months Ended
	Dec. 22, 2017	Dec. 21, 2017	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	Jun. 01, 2019	Mar. 02, 2019	Dec. 01, 2018	Sep. 01, 2018	Jun. 02, 2018	Feb. 29, 2020	Mar. 02, 2019	Dec. 31, 2018	Mar. 03, 2018
Federal statutory rate (as a percent)	35.00%	35.00%									21.00%	21.00%	21.00%	32.60%
Reconciliation of the expected statutory federal tax and the total income tax expense (benefit)
Federal statutory rate											$ (17,093,000)	$ (123,790,000)		$ (14,202,000)
Federal tax rate change			$ 347,599,000				$ 212,252,000							324,765,000
Nondeductible expenses											1,025,000	2,890,000		1,213,000
State income taxes, net											46,620,000	(12,605,000)		(22,836,000)
Increase/(decrease) of previously recorded liabilities											(4,477,000)	(3,105,000)		27,295,000
Nondeductible compensation											2,623,000	1,798,000		654,000
Officer life insurance											5,555,000
Qualified fringe disallowance											974,000
Acquisition costs														696,000
Stock based compensation											4,999,000	3,478,000		8,363,000
Valuation allowance											347,599,000	212,252,000		(8,853,000)
Other											(218,000)	(3,441,000)		(11,108,000)
Total income tax expense (benefit)			$ 351,729,000	$ 876,000	$ 27,628,000	$ 7,374,000	$ 195,004,000	$ (1,471,000)	$ (106,559,000)	$ (9,497,000)	387,607,000	77,477,000		305,987,000
Income tax (benefit) expense, discontinued operation											7,011,000	91,067,000		749,704,000
Discontinued operations
Reconciliation of the expected statutory federal tax and the total income tax expense (benefit)
Valuation allowance											$ 0	$ (2,417,000)		$ (32,870,000)