SEGMENTS - Method of Overhead Allocation (Detail 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 527,428	$ 909,865	$ 473,884	$ 432,965	$ 514,323	$ 812,330	$ 424,010	$ 366,192	$ 2,344,142	$ 2,116,855	$ 1,718,231
Long-Lived Assets	281,630				247,852				281,630	247,852	244,707
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,157,889	1,956,589	1,528,473
Long-Lived Assets	150,949				132,822				150,949	132,822	106,638
Non-United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									186,253	160,266	189,758
Long-Lived Assets	$ 130,681				$ 115,030				$ 130,681	$ 115,030	$ 138,069