Earnings per share (Schedule of Calculation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2023	May 31, 2022
Earnings Per Share [Abstract]
Net income	$ 12,090	$ 29,110	$ 35,764	$ 49,564
Weighted average shares outstanding (in shares)	43,343	43,575	43,321	43,778
Basic earnings per common share (in dollars per share)	$ 0.28	$ 0.67	$ 0.83	$ 1.13
Diluted earnings per common share:
Net income	$ 12,090	$ 29,110	$ 35,764	$ 49,564
Effect of dilution from common stock equivalents (in shares)	1,127	678	1,090	702
Diluted weighted average shares outstanding (in shares)	44,470	44,253	44,411	44,480
Diluted earnings per share (in dollars shares)	$ 0.27	$ 0.66	$ 0.81	$ 1.11