Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Statement of Comprehensive Income [Abstract]
Tax amount related to unrealized net gains on investment securities	$ (36,000)	$ (5,000)	$ (231,000)	$ (12,000)
Tax amount related to foreign currency translation adjustments	0	0	100,000	(604,000)
Tax amount related to unrealized net gains on interest rate derivative contracts	$ (1,562,000)	$ (3,670,000)	$ (12,338,000)	$ (5,169,000)