Income Taxes Difference of Effective Tax Rate from Federal Tax Rate (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Reconciliation of Statutory Federal Tax Rate
Federal tax, at statutory rate	$ 57,074	$ 49,467	$ 28,813
State tax, net of federal benefit	355	(65)	137
Impact of international operations including withholding taxes and other reserves	(46,632)	(50,275)	(53,499)
Repatriation of foreign subsidiary earnings	20,367	12,661	1,364
Foreign tax credits	(5,489)	(8,203)	(411)
Costs incurred for stock of acquired business	0	67	98
Tax credits (excluding foreign tax credits)	(12,571)	(11,782)	(9,677)
Amortization of deferred charge	(2,311)	0	323
Losses and tax credits for which no benefit has been realized	(5,929)	5,978	28,275
Stock-based compensation expense	2,593	1,895	2,947
Non-deductible meals and entertainment	1,087	1,021	1,096
Other, net	966	1,937	(529)
Provision (benefit) for income taxes	$ 9,510	$ 2,701	$ (1,063)