Income Taxes - Net Operating Losses and Tax Credits (Details) - USD ($) $ in Thousands	Feb. 29, 2020	Mar. 02, 2019
Net Operating Losses and Tax Credits
Net tax effect of state carryforwards	$ 1,046,331
Alternative minimum tax credit carryforwards	6,748
Valuation Allowance
Valuation allowance	1,673,119	$ 1,091,416
Federal
Net Operating Losses and Tax Credits
Net operating loss carryforwards	1,152,396
Federal business tax credit carryforwards	18,427
Federal | Tax Period Between Fiscal 2029 And 2031 [Member]
Net Operating Losses and Tax Credits
Net operating losses subject to expiration	900,383
Federal | Tax Period Between Fiscal 2032 and 2038
Net Operating Losses and Tax Credits
Net operating losses subject to expiration	178,246
State
Net Operating Losses and Tax Credits
Net operating loss carryforwards	$ 11,413,504