Net Income per Share Schedule of calculation of numerator and denominator in earnings per share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Numerator:
Net income attributable to Raven Industries, Inc.	$ 10,859	$ 11,390	$ 41,448	$ 39,567
Denominator:
Weighted average common shares outstanding (in shares)	36,306	36,194	36,279	36,170
Weighted average stock units outstanding (in shares)	57	48	54	54
Denominator for basic calculation (in shares)	36,363	36,242	36,333	36,224
Weighted average common shares outstanding (in shares)	36,306	36,194	36,279	36,170
Weighted average stock units outstanding (in shares)	57	48	54	54
Dilutive impact of stock options and restricted units (in shares)	167	196	207	206
Denominator for diluted calculation (in shares)	36,530	36,438	36,540	36,430
Net income per share - basic (in dollars per share)	$ 0.30	$ 0.31	$ 1.14	$ 1.09
Net income per share - diluted (in dollars per share)	$ 0.30	$ 0.31	$ 1.13	$ 1.09