Income Taxes Difference of Effective Tax Rate from Federal Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Disclosure Difference of Effective Tax Rate From Federal Tax Rate [Abstract]
Federal tax, at statutory rate	$ 64,700	$ 41,626	$ 58,725
State tax, net of federal benefit	684	(60)	900
Impact of international operations including withholding taxes and other reserves	(48,268)	7,143	(27,042)
Repatriation of foreign subsidiary earnings	55,812	354	21,969
Foreign tax credits	(10,739)	(2,382)	(5,143)
Tax credits (excluding foreign tax credits)	(12,180)	(11,539)	(8,089)
Change in deferred tax assets valuation allowance	(25,531)	(21,055)	(26,443)
Amortization of deferred charge	415	(167)	1,168
Stock-based compensation expense	489	3,402	2,929
Non-deductible meals and entertainment	1,247	1,177	1,238
Other, net	3,361	6,254	2,369
Provision (benefit) for income taxes	$ 29,990	$ 24,753	$ 22,581