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	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Numerator:
Net income attributable to Raven Industries, Inc.	$ 50,569	$ 40,537	$ 28,574
Denominator:
Weighted average common shares outstanding	18,091	18,042	18,021
Weighted average stock units outstanding	26	25	19
Denominator for basic calculation	18,117	18,067	18,040
Weighted average common shares outstanding	18,091	18,042	18,021
Weighted average stock units outstanding	26	25	19
Dilutive impact of stock options	110	43	3
Denominator for diluted calculation	18,227	18,110	18,043
Net income per share - basic	$ 2.79	$ 2.24	$ 1.58
Net income per share - diluted	$ 2.77	$ 2.24	$ 1.58