Significant Accounting Policies Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2020	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2021	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Schedule of Income Tax Expense [Line Items]
Proceeds and Excess Tax Benefit from Share-based Compensation					$ 796
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Percent					(7.00%)	(5.00%)	(16.00%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent					8.00%	2.00%	43.00%
Current Income Tax Expense (Benefit)					$ 38,983	$ 26,371	$ 15,419
Domestic Tax Authority [Member]
Schedule of Income Tax Expense [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	35.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount					220,935
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount					$ 7,260
Foreign Tax Authority [Member]
Schedule of Income Tax Expense [Line Items]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent					0.00%	(1.00%)	33.00%
Scenario, Forecast [Member] | Foreign Tax Authority [Member]
Schedule of Income Tax Expense [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	18.00%			17.00%