Common Stock (Other) (Details)															12 Months Ended
	Feb. 28, 2023 USD ($)	Feb. 01, 2023 USD ($) $ / shares	Dec. 06, 2022 USD ($)	Oct. 27, 2022 USD ($) $ / shares	Sep. 02, 2022 USD ($)	Aug. 05, 2022 USD ($)	Aug. 03, 2022 USD ($) $ / shares	Jun. 15, 2022 USD ($)	Jun. 02, 2022 USD ($)	May 04, 2022 USD ($) $ / shares	Jan. 25, 2022 USD ($)	Jan. 04, 2022 USD ($) $ / shares	Sep. 08, 2021 USD ($)	Jul. 30, 2021 USD ($) $ / shares	Mar. 31, 2023 USD ($) item shares	Mar. 31, 2022 USD ($)	Jul. 01, 2013 $ / shares shares
Common Stock:
Dividends declared (in dollars per share) | $ / shares		$ 1.00		$ 1.00			$ 1.00			$ 2.50		$ 1.00		$ 1.00
Dividends, Common Stock | $		$ 40,400,000		$ 40,400,000			$ 40,300,000			$ 100,300,000		$ 40,100,000		$ 40,400,000
Dividends paid in cash | $	$ 40,100,000		$ 40,100,000		$ 40,100,000	$ 400,000		$ 200,000	$ 99,700,000		$ 39,900,000		$ 40,200,000		$ 220,597,827	$ 80,082,210
Dividends payable | $	$ 300,000		$ 300,000		$ 200,000				$ 600,000		$ 200,000		$ 200,000		$ 1,255,861	$ 494,180
Common stock
Authorized capital stock (in shares) | shares																	500,000,000
Par value of capital stock (in dollars per share) | $ / shares																	$ 0.01
Common Stock, Shares Authorized | shares															450,000,000		450,000,000
Preferred Stock, Shares Authorized | shares															50,000,000		50,000,000
Number of votes entitled to shareholders | item															1