Intangible Assets - Details of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2019	Jan. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	$ 54,470	$ 54,470
Intangible assets, Accumulated amortization	(31,519)	(29,949)
Intangible assets, Net	22,951	24,521
Existing technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	3,880	3,880
Intangible assets, Accumulated amortization	(3,843)	(3,834)
Intangible assets, Net	$ 37	$ 46
Intangible assets, Remaining useful life	10 months 24 days	1 year 2 months 12 days
Database [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	$ 4,939	$ 4,939
Intangible assets, Accumulated amortization	(4,609)	(4,521)
Intangible assets, Net	$ 330	$ 418
Intangible assets, Remaining useful life	10 months 24 days	1 year 2 months 12 days
Customer contracts and relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	$ 33,643	$ 33,643
Intangible assets, Accumulated amortization	(13,201)	(12,350)
Intangible assets, Net	$ 20,442	$ 21,293
Intangible assets, Remaining useful life	6 years 4 months 24 days	6 years 7 months 6 days
Software [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	$ 10,867	$ 10,867
Intangible assets, Accumulated amortization	(8,725)	(8,156)
Intangible assets, Net	$ 2,142	$ 2,711
Intangible assets, Remaining useful life	10 months 24 days	1 year 2 months 12 days
Brand [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross carrying amount	$ 1,141	$ 1,141
Intangible assets, Accumulated amortization	$ (1,141)	(1,088)
Intangible assets, Net		$ 53
Intangible assets, Remaining useful life		2 months 12 days