Borrowings (Table Text Block)	3 Months Ended	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2020
Debt Instruments [Abstract]
Long-Term Debt		December 31,   March 31,   2020 Rates (a)     Maturities   2020   2020                 (Unaudited)                     (In thousands) Real estate loan (amortizing term)       1.65 %       2023 $ 85,413 $ 92,913 Senior mortgages 2.80 % - 6.62 %   2021 - 2038   2,143,383   2,029,878 Real estate loans (revolving credit) 1.55 % - 3.25 %   2022 - 2025   535,000   519,000 Fleet loans (amortizing term) 2.04 % - 4.66 %   2021 - 2027   169,840   224,089 Fleet loans (revolving credit)       1.30 %   2022 - 2024   547,000   567,000 Finance/capital leases (rental equipment) 1.92 % - 5.04 %   2021 - 2026   561,351   734,870 Finance liability (rental equipment) 1.60 % - 4.22 %   2024 - 2028   581,594   398,834 Other obligations 2.50 % - 8.00 %   2021 - 2049   84,877   84,484 Notes, loans and finance/capital leases payable                   4,708,458   4,651,068 Less: Debt issuance costs                     (30,231)   (29,777) Total notes, loans and finance/capital leases payable, net         $ 4,678,227 $ 4,621,291                             (a) Interest rates as of December 31, 2020, including the effect of applicable hedging instruments.
Annual Maturities of Notes, Loans and Leases Payable		Year Ending December 31,     2021   2022   2023   2024   2025   Thereafter     (Unaudited)     (In thousands) Notes, loans and finance/capital leases payable, secured $ 512,946 $ 868,852 $ 852,538 $ 612,298 $ 262,023 $ 1,599,801
Components of interest expense	Quarter Ended December 31,     2020   2019     (Unaudited)     (In thousands) Interest expense $ 41,371 $ 45,037 Capitalized interest   (2,105)   (5,775) Amortization of transaction costs   1,890   1,176 Interest expense effect resulting from cash flow hedges   972   (465) Total interest expense $ 42,128 $ 39,973	Nine Months Ended December 31,     2020   2019     (Unaudited)     (In thousands) Interest expense $ 124,882 $ 133,111 Capitalized interest   (10,033)   (17,943) Amortization of transaction costs   4,645   3,276 Interest expense effect resulting from cash flow hedges   2,680   (461) Total interest expense $ 122,174 $ 117,983
Interest rates and company borrowings	Revolving Credit Activity       Quarter Ended December 31,       2020   2019       (Unaudited)       (In thousands, except interest rates)   Weighted average interest rate during the period   1.66 % 3.09 % Interest rate at the end of the period   1.65 % 2.95 % Maximum amount outstanding during the period $ 1,082,000 $ 1,025,000   Average amount outstanding during the period $ 1,057,380 $ 1,014,511   Facility fees $ 91 $ 40	Revolving Credit Activity       Nine Months Ended December 31,       2020   2019       (Unaudited)       (In thousands, except interest rates)   Weighted average interest rate during the period   1.65 % 3.44 % Interest rate at the end of the period   1.65 % 2.95 % Maximum amount outstanding during the period $ 1,175,000 $ 1,025,000   Average amount outstanding during the period $ 1,092,382 $ 995,508   Facility fees $ 185 $ 147