Earnings per share - 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, 2022	May 31, 2021	May 31, 2022	May 31, 2021
Earnings Per Share [Abstract]
Net income	$ 29,110	$ 13,557	$ 49,564	$ 32,518
Weighted average shares outstanding (in shares)	43,575	43,818	43,778	43,963
Basic earnings per common share (in dollars per share)	$ 0.67	$ 0.31	$ 1.13	$ 0.74
Diluted earnings per common share:
Net income	$ 29,110	$ 13,557	$ 49,564	$ 32,518
Effect of dilution from common stock equivalents (in shares)	678	654	702	599
Diluted weighted average shares outstanding (in shares)	44,253	44,472	44,480	44,562
Diluted earnings per share (in dollars shares)	$ 0.66	$ 0.30	$ 1.11	$ 0.73