Provision for Taxes (Reconciliation of total amounts of unrecognized tax benefits roll forward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits beginning balance	$ 37,201	$ 35,739
Revaluation based on change in after tax benefit	0	0
Additions based on tax positions related to the current year	42	1,887
Reductions for tax positions of prior years	7,606	46
Settlements	5	379
Unrecognized tax benefits ending balance	$ 29,632	$ 37,201