Financial Information by Geographic Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Fiscal year ended:
Total revenues	$ 5,864,691	$ 5,739,747	$ 4,541,985
Depreciation and amortization, net of (gains) losses on disposals	520,315	512,486	641,504
Interest expense	223,958	167,424	163,502
Pretax earnings	1,217,923	1,475,497	796,658
Income tax expense	294,925	352,211	185,802
Identifiable assets	18,124,648	17,299,581	14,651,606
United States [Member]
Fiscal year ended:
Total revenues	5,570,264	5,452,027	4,334,083
Depreciation and amortization, net of (gains) losses on disposals	514,043	509,517	631,344
Interest expense	221,008	163,586	160,429
Pretax earnings	1,178,264	1,431,155	773,030
Income tax expense	285,724	342,213	180,845
Identifiable assets	17,453,015	16,776,070	14,212,978
Canada [Member]
Fiscal year ended:
Total revenues	294,427	287,720	207,902
Depreciation and amortization, net of (gains) losses on disposals	6,272	2,969	10,160
Interest expense	2,950	3,838	3,073
Pretax earnings	39,659	44,342	23,628
Income tax expense	9,201	9,998	4,957
Identifiable assets	$ 671,633	$ 523,511	$ 438,628