Background and Summary of Significant Accounting Policies - Other assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Other Assets Noncurrent [Abstract]
Right of use assets - Operating leases	$ 31,237	$ 24,875
Investments in unconsolidated affiliates	11,861	9,250
Capitalized software development costs, net	11,170	11,045
Deposits	4,649	3,842
Central parts	7,015	6,745
Other	19,559	13,383
Total other assets	$ 85,491	$ 69,140