OTHER CURRENT AND NONCURRENT ASSETS: (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Other current assets
Prepaid expenses and other	$ 25,823	$ 27,594
Assets of non-qualified retirement plan	14,344	13,551
Other current assets	40,167	41,145
Other noncurrent assets
Acquired intangible assets, net	31,453	33,922
Deferred data acquisition costs	879	1,036
Other miscellaneous noncurrent assets	8,626	6,510
Noncurrent assets	$ 40,958	$ 41,468