Leases, Balance Sheet Information (Details) - USD ($)	Jun. 30, 2021	Mar. 31, 2021
Assets [Abstract]
Operating, Operating lease assets	$ 87,924,000	$ 71,513,000
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Operating, Operating lease assets	Operating, Operating lease assets
Finance, Plant and equipment	$ 8,592,000	$ 8,852,000
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Plant and equipment - net	Plant and equipment - net
Total leased assets	$ 96,516,000	$ 80,365,000
Current [Abstract]
Operating, Operating lease liabilities	$ 5,434,000	$ 6,439,000
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Operating, Operating lease liabilities	Operating, Operating lease liabilities
Finance, Other current liabilities	$ 2,584,000	$ 2,640,000
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Current	Other Liabilities, Current
Long-term [Abstract]
Operating, Long-term operating lease liabilities	$ 85,889,000	$ 70,551,000
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Operating, Long-term operating lease liabilities	Operating, Long-term operating lease liabilities
Finance, Other liabilities	$ 4,606,000	$ 4,995,000
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Total lease liabilities	$ 98,513,000	$ 84,625,000