Fair Value Measurements (Schedule Of Financial Instruments) (Details) (USD $)	Jul. 31, 2012		Jan. 31, 2012
Financial Assets:
Financial assets	$ 162,452,000		$ 218,819,000
Derivative assets	241,000		1,214,000
Financial Liabilities:
Derivative liabilities	3,703,000		530,000
Contingent consideration liabilities associated with business combinations	25,204,000		38,646,000
Financial liabilities	28,907,000		39,176,000
Commercial Paper
Financial Assets:
Financial assets	9,386,000	[1]	9,383,000	[1]
Money Market Funds
Financial Assets:
Financial assets	152,825,000	[1]	207,950,000	[1]
Auction Rate Securities
Financial Assets:
Financial assets			272,000
Commercial Paper And Money Market Funds
Financial Liabilities:
Cash and cash equivalents	160,100,000		215,200,000
Restricted cash and bank deposits	2,100,000		2,100,000
Quoted Prices to Active Markets For Identical Instruments (Level 1)
Financial Assets:
Financial assets	152,825,000		207,950,000
Derivative assets	0		0
Financial Liabilities:
Derivative liabilities	0		0
Contingent consideration liabilities associated with business combinations	0		0
Financial liabilities	0		0
Quoted Prices to Active Markets For Identical Instruments (Level 1) | Commercial Paper
Financial Assets:
Financial assets	0	[1]	0	[1]
Quoted Prices to Active Markets For Identical Instruments (Level 1) | Money Market Funds
Financial Assets:
Financial assets	152,825,000	[1]	207,950,000	[1]
Quoted Prices to Active Markets For Identical Instruments (Level 1) | Auction Rate Securities
Financial Assets:
Financial assets			0
Significant Other Observable Inputs (Level 2)
Financial Assets:
Financial assets	9,627,000		10,597,000
Derivative assets	241,000		1,214,000
Financial Liabilities:
Derivative liabilities	3,703,000		530,000
Contingent consideration liabilities associated with business combinations	0		0
Financial liabilities	3,703,000		530,000
Significant Other Observable Inputs (Level 2) | Commercial Paper
Financial Assets:
Financial assets	9,386,000	[1]	9,383,000	[1]
Significant Other Observable Inputs (Level 2) | Money Market Funds
Financial Assets:
Financial assets	0	[1]	0	[1]
Significant Other Observable Inputs (Level 2) | Auction Rate Securities
Financial Assets:
Financial assets			0
Significant Unobservable Inputs (Level 3)
Financial Assets:
Financial assets	0		272,000
Derivative assets	0		0
Financial Liabilities:
Derivative liabilities	0		0
Contingent consideration liabilities associated with business combinations	25,204,000		38,646,000
Financial liabilities	25,204,000		38,646,000
Significant Unobservable Inputs (Level 3) | Commercial Paper
Financial Assets:
Financial assets	0	[1]	0	[1]
Significant Unobservable Inputs (Level 3) | Money Market Funds
Financial Assets:
Financial assets	0	[1]	0	[1]
Significant Unobservable Inputs (Level 3) | Auction Rate Securities
Financial Assets:
Financial assets			$ 272,000

[1] July 31, 2012 and January 31, 2012, commercial paper and money market funds of $160.1 million and $215.2 million, respectively, were classified in “Cash and cash equivalents” and as of each such date $2.1 million of money market funds were classified in “Restricted cash and bank time deposits” within the condensed consolidated balance sheets.