Interest Rate Cap Agreements (Schedule of Fair Value of Derivative Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Derivatives Fair Value [Line Items]
Other noncurrent assets, net	$ 503,405	$ 430,141
Accrued expenses	(463,510)	(484,293)
Other long-term liabilities	(62,411)	(65,572)
Fair Values of Derivative Instruments Asset (Liability) Derivatives	(8,857)
Designated as Hedging Instrument [Member] | Interest Rate Cap Agreements [Member]
Derivatives Fair Value [Line Items]
Other noncurrent assets, net	8
Accrued expenses	(8,666)	(22,360)
Other long-term liabilities	(53)	(365)
Fair Values of Derivative Instruments Asset (Liability) Derivatives	$ (8,711)	$ (22,725)