Term Receivable and Trade Accounts Receivable Balances (Detail) - USD ($) $ in Thousands	Oct. 31, 2015	Jan. 31, 2015
Accounts and Financing Receivable [Line Items]
Trade accounts receivable, net	$ 447,760	$ 546,622
Term receivables, long-term	283,756	301,862
Trade accounts receivable
Accounts and Financing Receivable [Line Items]
Trade accounts receivable, net	113,243	208,996
Term receivables, short-term
Accounts and Financing Receivable [Line Items]
Trade accounts receivable, net	$ 334,517	$ 337,626