OTHER CURRENT AND NONCURRENT ASSETS: (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Other current assets
Prepaid expenses and other	$ 12,737	$ 9,058
Income Taxes Receivable	7,658	0
Post-closing receivable from IPG	0	17,625
Interest receivable	648	2,497
Assets of non-qualified retirement plan	11,623	14,970
Other current assets	32,666	44,150
Other noncurrent assets
Internally developed software	889	2,486
Right-of-use asset (see Note 2)	17,830	0
Deferred tax asset	852	35
Deposits	2,562	2,463
Other miscellaneous noncurrent assets	5,032	5,819
Other assets, net	$ 27,165	$ 10,803