Leases, Balance Sheet Information (Details) - USD ($)	Dec. 31, 2020	Mar. 31, 2020
Assets [Abstract]
Operating, Operating lease assets	$ 74,685,000	$ 53,029,000
Finance, Plant and equipment	8,559,000	6,922,000
Total leased assets	83,244,000	59,951,000
Current [Abstract]
Operating, Operating lease liabilities	6,232,000	5,104,000
Finance, Other current liabilities	2,555,000	2,059,000
Long-term [Abstract]
Operating, Long-term operating lease liabilities	71,569,000	61,425,000
Finance, Other liabilities	4,981,000	3,905,000
Total lease liabilities	$ 85,337,000	$ 72,493,000