INCOME TAXES (Details) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Current:
Federal	$ 25,530,000	$ 23,844,000	$ 22,601,000
State	2,452,000	2,719,000	1,077,000
Foreign	4,777,000	5,080,000	5,888,000
Total current provision for income taxes	32,759,000	31,643,000	29,566,000
Deferred [Abstract]
Federal	(586,000)	2,324,000	475,000
State	(474,000)	(569,000)	1,262,000
Foreign	324,000	168,000	110,000
Total deferred benefit for income taxes	(736,000)	1,923,000	1,847,000
Income tax expense	32,023,000	33,566,000	31,413,000
Components of income before income taxes
United States	80,875,000	79,589,000	75,426,000
Foreign	57,550,000	63,013,000	65,230,000
Income before income taxes	138,425,000	142,602,000	140,656,000
Reconciliation between statutory federal income taxes and income tax expense
Tax expense at statutory rate	48,449,000	49,911,000	49,229,000
Foreign operations taxed at different rates	(15,244,000)	(16,973,000)	(16,308,000)
State taxes, net of federal benefit	1,978,000	2,149,000	2,340,000
Research and development credit	(3,380,000)	(1,392,000)	(3,234,000)
Other, net	220,000	(129,000)	(614,000)
Income tax expense	32,023,000	33,566,000	31,413,000
Effective tax rate	23.10%	23.50%	22.30%
Permanently reinvested foreign earnings	546,000,000
Components of Deferred Tax Assets [Abstract]
Accruals and other reserves	7,983,000	9,822,000
Net operating loss carry forward	5,956,000	6,317,000
Stock compensation	8,199,000	1,388,000
Other deferred tax assets	3,643,000	3,561,000
Valuation allowance	(5,984,000)	(6,088,000)
Total deferred tax assets	19,797,000	15,000,000
Components of Deferred Tax Liabilities [Abstract]
Deferred gains on sales of properties	(1,756,000)	(1,881,000)
Purchased intangibles	(11,000)	(143,000)
Unremitted earnings of certain subsidiaries	(3,064,000)	(3,064,000)
Fixed asset depreciation	(4,402,000)	(5,309,000)
Other deferred tax liabilities	(2,186,000)	(2,186,000)
Total deferred tax liabilities	(11,419,000)	(12,583,000)
Net deferred tax assets	8,378,000	2,417,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	11,141,000	10,458,000	11,201,000
Increase (decrease) of unrecognized tax benefits related to prior years	(117,000)	116,000	(960,000)
Increase of unrecognized tax benefits related to the current year	2,430,000	2,074,000	2,185,000
Reductions to unrecognized tax benefits related to lapse of applicable statute of limitations	(2,382,000)	(1,507,000)	(1,968,000)
Balance at end of period	11,072,000	11,141,000	10,458,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	2,000,000	1,700,000
Accrued penalties related to unrecognized tax benefits	$ 0	$ 0