| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] |
| | | | | (in thousands, except share and per share amounts) | | | | | 2018
through
April 30,
2019 | | | Net loss (numerator): | | | | | | | | | | Net loss attributable to Concrete Pumping Holdings, Inc. | | $ | (9,645 | ) | | $ | (13,275 | ) | | Less: Preferred stock - cumulative dividends | | | (434 | ) | | | (703 | ) | | Net loss available to common shareholders | | $ | (10,079 | ) | | $ | (13,978 | ) | | | | | | | | | | | | Weighted average shares (denominator): | | | | | | | | | | Weighted average shares - basic | | | 29,166,165 | | | | 29,043,174 | | | Weighted average shares - diluted | | | 29,166,165 | | | | 29,043,174 | | | | | | | | | | | | | Basic loss per share | | $ | (0.35 | ) | | $ | (0.48 | ) | | Diluted loss per share | | $ | (0.35 | ) | | $ | (0.48 | ) | | | | | | | | | 2018
through
December 5,
2018 | | | | | | 2017
through
April 30,
2018 | | | Net loss (numerator): | | | | | | | | | | | | | | Net (loss) income attributable to Concrete Pumping Holdings, Inc. | | $ | (22,575 | ) | | $ | 4,611 | | | $ | 22,168 | | | Less: Preferred stock - cumulative dividends | | | (126 | ) | | $ | (342 | ) | | | (684 | ) | | Less: Undistributed earnings allocated to preferred shares | | | - | | | $ | (1,008 | ) | | | (5,073 | ) | | Net (loss) income available to common shareholders | | $ | (22,701 | ) | | $ | 3,261 | | | $ | 16,411 | | | | | | | | | | | | | | | | | Weighted average shares (denominator): | | | | | | | | | | | | | | Weighted average shares - basic | | | 7,576,289 | | | | 7,576,289 | | | | 7,576,289 | | | Dilutive effect of stock options | | | - | | | | 816,492 | | | | 816,492 | | | Weighted average shares - diluted | | | 7,576,289 | | | | 8,392,781 | | | | 8,392,781 | | | | | | | | | | | | | | | | | Basic income (loss) per share | | $ | (3.00 | ) | | $ | 0.43 | | | $ | 2.17 | | | Diluted income (loss) per share | | $ | (3.00 | ) | | $ | 0.39 | | | $ | 1.96 | | |