Net Income per Share - Schedule of calculation of numerator and denominator in earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Jan. 31, 2019		Oct. 31, 2018		Jul. 31, 2018		Apr. 30, 2018		Jan. 31, 2018		Oct. 31, 2017		Jul. 31, 2017		Apr. 30, 2017		Jan. 31, 2019		Jan. 31, 2018		Jan. 31, 2017
Numerator:
Net income attributable to Raven Industries, Inc.	$ 2,950	[1]	$ 13,032	[1]	$ 13,677	[1]	$ 22,135	[1]	$ 8,441		$ 11,998		$ 8,235		$ 12,348		$ 51,794	[1]	$ 41,022		$ 20,191
Denominator:
Weighted average common shares outstanding (in shares)																	35,907,041		35,945,225		36,142,416
Weighted average stock units outstanding (in shares)																	99,922		104,980		100,019
Denominator for basic calculation (in shares)																	36,006,963		36,050,205		36,242,435
Weighted average common shares outstanding (in shares)																	35,907,041		35,945,225		36,142,416
Weighted average stock units outstanding (in shares)																	99,922		104,980		100,019
Dilutive impact of stock options and RSUs (in shares)																	431,595		399,620		129,480
Denominator for diluted calculation (in shares)																	36,438,558		36,449,825		36,371,915
Net income per share - basic (in usd per share)	$ 0.08	[2]	$ 0.36	[2]	$ 0.38	[2]	$ 0.62	[2]	$ 0.24	[2]	$ 0.33	[2]	$ 0.23	[2]	$ 0.34	[2]	$ 1.44	[2]	$ 1.14	[2]	$ 0.56
Net income per share - diluted (in usd per share)	$ 0.08	[2]	$ 0.36	[2]	$ 0.38	[2]	$ 0.61	[2]	$ 0.23	[2]	$ 0.33	[2]	$ 0.23	[2]	$ 0.34	[2]	$ 1.42	[2]	$ 1.13	[2]	$ 0.56

[1] The TCJA, effective January 1, 2018, had a favorable impact to the Company's effective tax rate. Excluding discrete items, the Company's effective tax rate decreased approximately 10 percentages points resulting in tax savings of $6,218 in fiscal year 2019.

[2] Net income per share is computed discretely by quarter and may not add to the full year.