SeaChange International, Inc. Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Summary of Available-for-Sale Securities (Detail)

Fair Value Measurements - Summary of Available-for-Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	$ 104,285	$ 128,085
Gross Unrealized Gains	43	18
Gross Unrealized Losses	0	0
Estimated Fair Value	104,328us-gaap_AvailableForSaleSecurities	128,103us-gaap_AvailableForSaleSecurities
Cash [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	88,444	112,271
Gross Unrealized Losses	0	0
Estimated Fair Value	88,444	112,271
Cash Equivalents [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	1,575	3,463
Gross Unrealized Losses	0	0
Estimated Fair Value	1,575	3,463
Cash and Cash Equivalents [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	90,019	115,734
Gross Unrealized Losses	0	0
Estimated Fair Value	90,019	115,734
U.S. Treasury Notes and Bonds - Short Term [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	1,500	3,540
Gross Unrealized Gains	1	5
Gross Unrealized Losses	0	0
Estimated Fair Value	1,501	3,545
U.S. Treasury Notes and Bonds - Long Term [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	4,268
Gross Unrealized Gains	18
Gross Unrealized Losses	0
Estimated Fair Value	4,286
U.S. Government Agency Issues Short Term [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	6,008	2,005
Gross Unrealized Gains	7	5
Gross Unrealized Losses	0	0
Estimated Fair Value	6,015	2,010
U.S. Government Agency Issues Long Term [Member]
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	2,490	6,806
Gross Unrealized Gains	17	8
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 2,507	$ 6,814