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		6 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012	Jul. 31, 2011
Numerator:
Net income attributable to Raven Industries, Inc.	$ 11,546	$ 12,461	$ 30,589	$ 28,177
Denominator:
Weighted average common shares outstanding (in shares)	36,286	36,166	36,265	36,158
Weighted average stock units outstanding (in shares)	57	58	53	56
Denominator for basic calculation (in shares)	36,343	36,224	36,318	36,214
Weighted average common shares outstanding (in shares)	36,286	36,166	36,265	36,158
Weighted average stock units outstanding (in shares)	57	58	53	56
Dilutive impact of stock options and restricted units (in shares)	222	206	227	214
Denominator for diluted calculation (in shares)	36,565	36,430	36,545	36,428
Net income per share - basic (in dollars per share)	$ 0.32	$ 0.34	$ 0.84	$ 0.78
Net income per share - diluted (in dollars per share)	$ 0.32	$ 0.34	$ 0.84	$ 0.77