Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2017	Jan. 31, 2017
Income Taxes [Line Items]
Unrecognized tax benefits	$ 43,900
Unrecognized tax benefits including interest	$ 5,420	$ 1,905
U.S. federal tax authorities [Member] | Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year	2013
U.S. federal tax authorities [Member] | Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year	2017
U.S. state tax authorities [Member] | Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year	2007
U.S. state tax authorities [Member] | Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year	2017
Foreign tax authorities [Member] | Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year	2011
Foreign tax authorities [Member] | Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year	2017