OTHER CURRENT AND NONCURRENT ASSETS: (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Mar. 31, 2012
Other current assets
Prepaid expenses	$ 44,815	$ 43,768
Assets of non-qualified retirement plan	13,854	13,344
Other miscellaneous assets	321	692
Total other current assets	58,990	57,804
Other noncurrent assets
Other miscellaneous noncurrent assets	2,136	2,172
Other assets	2,933	3,697
Customer relationship intangibles
Other noncurrent assets
Acquired intangible assets, net	$ 797	$ 1,525