Combined Notes to the Financial Statements (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions						1 Months Ended		2 Months Ended	3 Months Ended
	May 01, 2020	Apr. 21, 2020	Apr. 20, 2020	Apr. 17, 2020	Mar. 10, 2020	May 31, 2020	Apr. 30, 2020	Apr. 30, 2020	Mar. 31, 2020	Mar. 31, 2019
Unusual or Infrequent Item, or Both [Line Items]
Net income (loss)									$ (1,704.0)	$ 292.0
Forecast
Unusual or Infrequent Item, or Both [Line Items]
Percent of capacity cut						90.00%
Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Percent of capacity cut							80.00%
Rolling cancellation period	60 days
Proceeds from issuance of secured term loans								$ 3,000.0
Proceeds from the issuance of common stock		$ 1,100.0
Number of shares issued (in shares)		43,175,000
Total funding provided under the Payroll Support Program			$ 5,000.0
Funding provided through loans under the Payroll Support Program			1,500.0
Funding provided through direct grants under the Payroll Support Program			$ 3,500.0
Number of securities called by warrants (in shares)			4,600,000
Warrant exercise price (in dollars per share)			$ 31.50
Warrant term			5 years
Support funding received		$ 2,500.0
Expected number of securities called by warrants (in shares)				14,200,000
Expected exercise price of warrants (in dollars per share)				$ 31.50
Unsecured Debt | PSP Note | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Face amount			$ 714.0
Percent increase in the principal amount based on any disbursement made by the U.S. Treasury Department			30.00%
Term of debt			10 years
Unsecured Debt | PSP Note | Years 1 through 5 | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Stated interest rate			1.00%
Secured Debt | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Expected borrowings				$ 4,500.0
Expected term of debt				5 years
Initial Issuance | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Number of securities called by warrants (in shares)			2,300,000
SOFR | Unsecured Debt | PSP Note | Years 6 through 10 | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Percent spread on variable rate			2.00%
CEO and President
Unusual or Infrequent Item, or Both [Line Items]
Voluntary pay reduction					100.00%
Officers
Unusual or Infrequent Item, or Both [Line Items]
Voluntary pay reduction					50.00%
Non-Employee Directors
Unusual or Infrequent Item, or Both [Line Items]
Voluntary pay reduction					100.00%