REVENUES FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2023	Oct. 31, 2022	Oct. 31, 2023	Oct. 31, 2022	Jan. 31, 2023
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized	$ 53.8	$ 48.7	$ 94.2	$ 127.6
Retained amounts by project owners	$ 19.2		$ 19.2		$ 49.1
Amounts of unpriced change orders included in transaction prices	6.7		6.7		11.6
Kilroot Project | APC
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Estimated loss	$ 7.9
Estimated loss, including reversal of net gross profit	10.7		$ 11.5
Reversal of profit	$ 2.8		$ 3.6