OTHER CURRENT AND NONCURRENT ASSETS: (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Other current assets
Prepaid expenses and other	$ 27,995	$ 25,714
Escrow deposit	5,880	5,880
Note receivable	0	4,000
Assets of non-qualified retirement plan	13,519	12,716
Other current assets	47,394	48,310
Other noncurrent assets
Acquired intangible assets, net	38,735	43,884
Deferred data acquisition costs	988	1,116
Other miscellaneous noncurrent assets	5,084	6,443
Noncurrent assets	$ 44,807	$ 51,443