Leases (Right-of-use Assets and Lease Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 106,790
Finance Lease, Right-of-Use Asset	$ 2,085
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAbstract
Total right-of-use assets	$ 108,875
Current liabilities: Operating leases	32,060
Current liabilities: Finance leases	$ 588
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Long Term Debt Current
Noncurrent liabilities: Operating leases	$ 88,239
Noncurrent liabilities: Finance leases	$ 1,554
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term Debt, Excluding Current Maturities
Total lease liabilities	$ 122,441