Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012	Jan. 31, 2013
Income Taxes (Textual) [Abstract]
Prepaid income taxes	$ 7,023,000		$ 7,023,000		$ 5,591,000
Prepaid foreign taxes	4,900,000		4,900,000		4,200,000
Prepaid domestic federal and state taxes	2,100,000		2,100,000		1,400,000
Net reduction in consolidated income tax expenses		141,000		141,000
Recognized tax benefit	3,300,000	5,300,000	3,300,000	5,300,000
Reversed estimates of potential penalties and interest			$ 1,900,000
Effective tax rate without impact	28.30%	13.50%	19.30%	22.50%
Federal statutory rate			34.00%