Consolidated Statement Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 37,268	$ 36,506	$ 115,381	$ 116,273
Other comprehensive (loss) income:
Foreign currency translation adjustment	(54,159)	(55,771)	174,942	(36,769)
Total comprehensive (loss) income	$ (16,891)	$ (19,265)	$ 290,323	$ 79,504